In Bakugan Battle Brawlers, the Bakugan (actually aliens from another world turned Card Game) are actually sentient beings who had their self-awareness suppressed due to negative energy. When they regain their sanity, the forces of darkness try to crush them...
In the New Vestroia season, there is actually a government conspiracy lead by the King of the Vestals to keep the fact that Bakugan are self aware a secret from the rest of the population...
The ELS in Gundam 00 Awakening Of The Trailblazer are at first somewhat single-minded and simplistic in action, and some of the characters in the series remain unconvinced that they are truly sentient until, near the end, the ELS are observed adapting their tactics and countering the humans' strategies in battle. One character even exclaims "They're learning!"
The Vajra encountered in Macross Frontier come off as a bit of a scientific dilemma: they're spacefaring critters with apparently eusocial behavior that can overpower starships, but they themselves have little centralization in their nervous systems (i.e. "no brains"). At first it isn't clear if they even communicate with each other. Only later, when they started using complex military tactics and began reacting to Ranka's and Sheryl's singing, was it made clear that they have some sort of guiding intellect. In the end, it was obvious: the Vajra aren't individuals per-se, they're more like individual cells. The "Vajra" organism is, in fact, the entire species, spread throughout the Galaxy, and communicating with itself via cellular-level Subspace Ansibles.
The Space Whales from Macross Dynamite 7 are initially thought to just be animals. Very big, very powerful animals, but nonetheless. The poachers trying to kill them are the first to notice that the Whales can identify who is actually a threat and choose their targets (they do not harm the good guys, who are trying to protect them), while everyone else seems to realize they're smarter than they look when Basara sings to them and they start singing back.
Mazinger Z: In the Mazinger-Z vs Great General of Darkness, when Kouji faces Mykene'sWar Beasts for first time, he -accostumed to the mindless, silent drones that Dr. Hell used- gets utterly shocked when they begin talking to him. Quickly learns that that is not the only difference with the Mechanical Beasts. They are intelligent, capable to think on their own, devise complex strategies, fight coordinatedly and even lay traps. Oh, and they are Dangerously Genre Savvy, too (they dragged and dunked Mazinger in the ocean, knowing that his robot's mobility is crap underwater, unlike the aquatic Beast that was waiting for him).
Kouji: It talks!
Several unique Titans in Attack on Titan shows signs of having intelligence, in contrast to most that are little more than mindless animals. This makes sense, since they are actually people capable of transforming into a Titan form and therefore maintain their human intelligence.
The Ape Titan takes it to another level. Not only can it think, it can talk.
The first instance occurs when the Rogue Titan puts up its fists in a boxer's stance and scores a One-Hit Kill on an enemy with a carefully aimed left hook to its weak spot.
Inverted in Robert Kirkman's Destroyer miniseries, where Keane battles a giant monster and brutally rends it limb from limb with his inhuman strength. Later he reveals that only after he'd torn its tongue out did he realize it was only about as intelligent as a dolphin (as opposed to the terrorists and supervillains he's much more sanguine about killing) and meant no actual harm, guiltily likening the experience to beating a dog.
In Stars Above, the Nine are revealed as Demons that can think, plan, and work together, making them far more human than the animalistic Demons that Homura has faced before.
Most notably in the scene in Aliens where the power is cut off moments before the aliens attack. In a later scene the Queen Alien clearly appreciates the danger Ripley presents to her eggs, indicating for her warriors to back off when Ripley threatens them with a flamethrower. She's also able to operate the lift to pursue Ripley. The only thing they didn't understand was that the overloading atmospheric processor...
In Alien: Resurrection, the captive xenomorph immediately realises the connection between the blasts of cold-gas that hit it and the Big Red Button, backing off the instant the scientist moves to hit it a second time. This later serves to bite the ass of a security mook. Likewise the aliens wait till communications are cut off (during security's fight with the mercenaries) before implementing their escape. They also notice that the Big Red Button was locked up at the time. They later lay a trap by herding the humans towards their egg room.
The Alan Dean Foster novelisations bring up this trope several times. Ash suggests they try communicating with the creature as it might be intelligent. The second book has Bishop bringing up the ant analogy and pointing out that the aliens have nested themselves in the one place the humans can't destroy them without destroying themselves (next to the cooling units of the fusion-powered atmosphere processor). And Alien³ had the xenomorphs actually reading the signs outside their cells, which kind of spoils the whole mystery.
Alien vs. Predator shows the Xenomorphs can work around predator setups just as well as human rigs. When the queen realized she couldn't get out of the shackles, she called back all of her offspring and ordered them to attack her so that her blood would corrode the shackles and free her.
Jurassic Park. Muldoon demands that the velociraptors be killed as they're far too intelligent; testing the electric fence for weaknesses (but never the same spot twice, "They remember," he warns) before they were moved to their high-walled prison. They seem to realise when the power is cut and claw their way through the electrified wire at the top. Even Muldoon underestimates their intelligence — as he's stalking one velociraptor, another ambushes him from the side. His Famous Last Words are a genuinely admiring, "Clever girl...."
Done even more explicitly in Jurassic Park III, where it's implied the raptors' intelligence is improving. At one point, two characters are pinned behind a mesh door by a raptor. After trying in vain to get at them, it looks up at the gap between door and ceiling and begins climbing the door. There's another scene where the raptors leave one injured man alive and hide nearby, waiting for the other humans to come out of hiding to help him. And that's not even mentioning the revelation that the raptors have their own language.
It's not so much that they are outwitted but rather that they were distracted. Like any animal, they have a instinct to investigate any strange noise they hear. That doesn't excuse them from not learning, though, which any intelligent animal would do from its mistakes.
Jaws. The shark hunters finally realize that the shark is hunting them.
Deep Blue Sea. An underwater facility housing intelligent sharks. The sharks pulled a Batman-Gambit on the humans, herding them around so they'd flood the complex and sink it low enough for the sharks to escape! They even (possibly) learned how to turn an oven on while one of the humans was in it.
In Land of the Dead, the zombies become even smarter. The leader of the zombies, Big Daddy, learns how to use a machine gun(and teaches a female zombie how to use it), the zombie horde learns to ignore the "sky flowers"(fireworks) that the humans use to distract them, and one of the undead prove mentally competent enough to chop the hand off of a soldier who has just pulled the pin on his grenade.
And the ending is a remarkably hopeful example of this trope, since the zombies look at people who are still alive...and keep on shambling forward, taking no interest in attacking them. Apparently they became smart enough to get over their bloodlust.
In Tremors, the Graboids can not only think, but learn very quickly, to the dismay of the citizens of Perfection. Though they start out pretty much just grabbing at whatever's walking around, and smashing through things, later on they dig a trap, and one even figures out the dynamite-on-a-string trick.
Subverted, though, in the second movie, after the Graboids metamorphose into the next stage of their life cycle, three-foot-tall raptor things called Shriekers. Burt, who's dealt with the Graboids before, keeps mentioning their learning abilities as explanation for why the power and communications are suddenly cut off, and their escape vehicle's engine is destroyed. Later on, however, it turns out they were just attacking whatever was displaying heat. As one character put it, "You mean they're acting so smart because they're so stupid?"
And in the third film El Blanco, an albino Graboid that can't transform into a Shrieker, has gotten smart enough to understand that Burt can't kill until it comes onto his property.
The unfortunate campers in The Ruins realize the plant-like entity they're trapped with is mimicking their voices to lure them into a trap. It also mimics a cell phone ringtone further inside the ruin because it knows humans will go to that noise. When it learns of one girl's strong desire to cut herself, it proceeds to repeat her own words to her "I want to cut, I want to cut I want to cut IWANTTOCUT!"
Jumanji. The ominous drumbeat that draws people to uncovering the board game heavily implies that it wants to be found. It's stated outright when the young Alan and Sarah first play.
Young Alan: Uh, oh. The game thinks I rolled...
Young Sarah: What do you mean "the game thinks"?
Rudy the albino baryonyx in Ice Age 3 is smart enough to hold a grudge against an individual weasel, named Buck.
In the 2007 film remake of I Am Legend, Robert Neville ends up caught in a trap similar to the one he used, with his mannequin friend as bait, watching an infected man hold back a team of infected attack dogs until the sun sets...
The alternate ending also shows that It Can Feel. The creatures are only attacking to get back their friend.
In the film version of Starship Troopers, the humans just quickly assume that the Bugs are dumb, mindless animals, and just the idea of them being capable of intelligent thought is incredibly offensive. However, the humans learn their lesson once the Bugs spring a massive trap and repel the initial human invasion force. It's later revealed that they are being led by extremely intelligent "Brain Bugs", a leadership caste. Keep in mind the war began when the bugs hit Earth with an asteroid from the other side of the galaxy and hit a population center to boot (although this is heavily implied to be a lie for propoganda purposes).
Godzilla has shown a surprising amount of intelligence in several films.
At one point late in Deep Rising, the monsters start herding the remaining humans towards their feeding area.
In Cube, this is applied to a structure instead of a monster, but it still fits the purposes of the trope. The protagonists openly wonder if the Cube is actually watching them and calculating. According to the sequels, there are human operators.
Munro: "I think they're smart — they're too damn smart."
The Day of the Triffids by John Wyndham. The exact level of intelligence of the genetically-engineered Man Eating Plants is a subject for debate, with the first-person protagonist (who worked on a triffid farm) rubbishing the idea that triffids are intelligent — after all, dissections haven't found anything remotely like a brain. Others are not so sure. One man points out that the triffids escaped from their farms within hours of everyone going blind. In another scene a triffid is waiting outside the very door which a person would run out of if they heard someone driving down the road.
One of the protagonist's former (he's presumably blinded and then killed like most other people), who also happens to be a worker at the same Triffid farm knows that they're intelligent, and has been trying to decipher their language (rattling stick-like limbs against their hollow stems). He also notes that they always go for the eyes, having figured out that this is humanity's greatest strength, that is intelligence.
In Peter F. Hamilton's short story, "Deathday" (found in the A Second Chance at Eden collection) there's a guy who had just buried his wife on an abandoned colony world. He starts having dreams of her turning into a local shapeshifting critter called a "slitherskin", which scientists had speculated was also mildly psychic as a defense mechanism. Scandalized by this invasion of his mind, the guy goes on a crusade to kill the animal snooping around his house, even remarking at the end that "like every cornered animal, it charged". He later goes back to deposit his rifle at his wife's grave. The next day, he finds that the creature had layed eggs (also a bit psychic) diguised as rocks at the gravesite. The last thing he sees is one of the slitherskin hatchlings taking the rifle, and pulling the trigger.
At the Mountains of Madness by HP Lovecraft. The expedition to Antarctica uncovers some fossils of what they assume are prehistoric plants and begin dissecting them. The narrator later discovers the camp wrecked, and the dogs and scientists all killed except for one missing man, who they assume went insane. It's only when they find his dissected body that they realise the horrible truth — the so-called fossils are actually sentient aliens capable of hibernating for millennia, and once had a civilization superior to man's.
Variation in the Sword of Truth books. We're told early on that short tailed gars are more intelligent than the long tailed variety, and Zedd even has a brief conversation with one (consisting of threatening it, asking its name, and sending it to kill their pursuers), but even then they're mostly treated like animals. In later books, however, it turns out they're quite intelligent, and a whole herd of the buggers pulls a Heel-Face Turn (or at least agrees to stop eating humans). It took them how long to realize the ''talking'' monsters were smart?
In Jeff VanderMeer's Ambergris-stories many characters express scepticism about the sentience or abilities of the Graycaps, but it's quite clear to the reader that they are quite possibly superhumanly intelligent and extremely dangerous when they want to be. The dual narrators of Shriek: An Afterword make a pretty good case of this being pure denial that the sceptics pursue to protect their own peace of mind.
Inverted in The War Against the Chtorr, where all the evidence of the Alien Invasion is that there must be some intelligence behind it, yet there's no sign of spaceships or any other means of crossing intersteller distances. The Chtorran gastropedes are assumed to be behind things, yet their intelligence is that of the idiot savant — they're very good at opening locks and can somehow communicate over distances, yet little else. The series appears to be implying that the entire Chtorran ecology is some form of group mind.
The Museum Beast/Mbwun from the novel and movieThe Relic is able to recognize traps, hide bodies, and do what it can to stay out of sight from humans, justified by the fact that it used to be human itself.
When the heroes in Codex Alera first come up against the Vordafter Tavi awakened them, it seems like it's going to be a case of "send in the army to exterminate the nest of mindless monsters." Unfortunately for them, it turns out that the Vord aren't just intelligent, but brilliant. Heck, the Queen set up all the circumstances for the Alerans' attack herself. And so a Malignant Plot Tumor was born...
In fact, the only reason the Aleran villagers survived the second book was because the Queen didn't expect self-sacrifice from humans. She was observing their tactics, recruiting their best fighters, upgrading her troops by researching their magic, etc. She was stunned at a bad moment upon realizing that their smartest tactician was Ax-Crazy (in her eyes).
In The Gnome's Engine, the townsfolk of Hob's Church have been trying to wipe out the local burrowing hobgoblins, considering them unintelligent, destructive pests. When a device under construction is sabotaged, one resident speculates that the hobgoblins did it, thinking it to be another hobgoblin-killing booby trap. One of the heroines calls him out on this ("They thought it was?"), and the accuser is horrified to realize that he, himself, isn't as convinced that hobgoblins are dumb animals as he'd believed. In fact, the hobgoblins are intelligent, but it's a human who sabotaged the device.
Subverted in World War Z, where the mercenary at the Long Island celebrities' fortress hears that their attackers can move quickly, and is frightened by the possibility that the zombies might think, too. It's a subversion because the attackers aren't zombies at all, but desperate civilians who'd seen the fortress's TV broadcasts, and are determined to seize this refuge for their families.
Non-monster variant: In Mrs. Frisby and the Rats of NIMH, we actually see this trope take effect upon Nicodemus in the laboratory as his intellect improves. Later, the sapient rats go to considerable lengths to avert this trope from their human pursuers' perspective, destroying all evidence of their more civilized lifestyle and even leaving a suicide-squad of naked fighters behind, at least some of whom are gassed to death, all to "prove" they're just ordinary rats.
In the Myth Adventures novels, the main character's pet dragon Gleep seems from his perspective to be roughly on the same intellectual level as a puppy. Later novels show things from the dragon's perspective, and reveal both that it is quite intelligent and that it considers the main character to be its pet.
Subverted in Stephen Baxter's Evolution, in the first flashback. There's mention of a dinosaur that's smarter than the others, but all this means is that it's "smart enough to go insane" - it submerges its survival instincts in order to hold a grudge against one of humanity's ancestors for eating its eggs.
In Brains: A Zombie Memoir, some of the human antagonists react this way to the protagonists, who are among the few zombies capable of intelligent thought.
Non-monster example: the ending of Jingo suggests that the Curious Squid are somewhat civilized and either built for themselves or adapted to living in the buildings on Leshp. They can't figure out why their city disappears above the sea every once in a while, though.
In The Long Dark Teatime Of The Soul, Dirk Gently has a crazed eagle trapped in his house, and is squinting through the keyhole trying to see where it is. He gets a nasty shock when he realises it's on the other side of the door, looking back through the keyhole at him. This is because it's actually a jet fighter transformed into an eagle with the mind of the pilot, for getting in Thor's way.
Three-quarters through Blindsight, the crew of the Theseus suddenly make the startling discovery that the "scramblers" they have been fighting, capturing, torturing and experimenting on are intelligent beings: They're intelligent without being sentient, a concept that was entirely alien to the crew up to that point and makes the "scramblers" so alien that trying to communicate with them meaningfully is impossible. At this point they also realise their "captives" let themselves get captured intentionally and have been spying on them. Things rapidly take a turn for the worse.
Basically the entire plot of the book Warm Bodies, where an encounter with a human survivor causes him to not only start coming back to life, but also to fall in love with her.
Holmes says this about Mary Russell in their first encounter. Russell is not pleased and gives him hell for it.
In the Star Trek episode "The Devil in the Dark", Spock deduces that not only is the monster intelligent, it has a valid reason for killing the miners. It turns out that the "crystals" the miners are collecting are actually the monster's eggs. Fortunately, the creature, called a Horta, is able to bargain with the humans to arrive at a mutually agreeable compromise.
EMH: Judging by these bio-scans the organism's been devouring life forms for a bit longer than thirty-nine years. I'd estimate it's at least 200,000 years old.
QATAI: The intelligent always survive.
EMH: I wouldn't go that far. It appears to operate on highly-evolved instinct. I haven't detected any signs of sentience.
QATAI: Oh, he's intelligent, all right. Smart enough to fool your crew into taking you offline.
This is quoted in GURPS: Magic 4th Edition. Page 100, Chapter 14 (Knowledge spells). It's played for horror here. The funny thing is that it's mentioned again in Chapter 17 (Meta-Spells) on page 121, where the actual enchantments are explained as well as how they work, and again in Chapter 24 (Technological spells), where the reaction in Chapter 14 is played for laughs.
Chapter 14: "This abomination thinks, somehow. It perceives, it decides, and it acts. Yet it does not live..."
Chapter 24: "My cell phone does that." "Well, yeah, but this doesn't have any mana chips in it or anything. It's all spells and analog enchantments." "Oh. So?" "I dunno. I guess that used to be a big deal..."
Pops up a lot in Warhammer 40,000 when the Tyranids are involved. Individually Tyranids are hyper-evolved killing animals, but the Hive Mind directing them has proven to be frighteningly intelligent.
Most followers of Khrone are mindless Axe Crazy Brutes however many of his top champions (like Kharn the Betrayer) are each a full on Genius Bruiser.
During the Great Crusade, to the few that he told anything about Warp entities, the Emperor denied this trope, leading several characters in the Horus Heresy series to realize it on their own.
The is frequently cited as the greatest danger of fighting the Orks: while the average Ork boy will be a Dumb MuscleBlood Knight and Ork Warboss is the strongest among them, he is also the smartest Ork in the Waaagh!, and sometimes can be pretty intelligent. Many human campaigns have failed due to underestimating the Orks intelligence.
Even dumb regular Orks still possess bestial cunning that often surprises their overconfident foes.
Promethean: The Created has Pandorans, mindless miscarriages of the process of creating a new Promethean who hunger endlessly for the vitriol of Prometheans. However, in rare occasions, a number of Pandorans can pull themselves together and form a Sublimatus, a fully-intelligent, nearly-human monstrosity that uses its new wits and cunning in an attempt to feast on Prometheans.
The witch in Into the Woods acknowledges this trope upon realizing a giant has entered the kingdom.
"With a giant, we'll all have to battle. A giant's the worst. A giant has a brain. Hard to outwit."
The X in Metroid Fusion, as Samus and the computer discover their capacity for intelligence over time. To the point of claiming a scientist so they can set the station's core to meltdown, destroying all of Samus's upgrade access points, and stealing an upgrade themselves.
Not to mention the fact that the icy, blue X which once targeted Samus for her newly-found weakness to the cold (due to her now part-Metroid DNA), start to run away from her soon after she recovers the Varia suit, which negates this weakness.
And invoked in Hearts of the Swarm. Kerrigan's broodmothers are capable of autonomy and building up a force, but lack the strategic vision to be truly dangerous, so she has them intentionally made smarter. When pointed out this makes them a danger to her, too, she says she wants them as dangerous as possible.
The Primal Zerg that remain on Zerus, unlike the Zerg that were integrated into a Hive Mind by the Xel'Naga, are sapient intelligent predators that have spent generations hunting, killing, and adapting. They consider the other Zerg to be corrupted.
Everyone thought the Voltigaunts of Half-Life were just dumb slaves. Turns out, they really aren't in the sequel.
Combine Gunships of Half-Life 2 are smart enough to realize that rockets are the only thing capable of harming them, so they accordingly try to shoot any enemy-fired rockets down. Also, a Fast Zombie in Episode 1 will, if you throw a grenade at it, lob the grenade right back.
The Nemesis from Resident Evil 3: Nemesis. Unlike all the other monsters up to this point, it is smart enough to follow orders, track the main character, open doors, use weapons, set ambushes, and speak (albeit only one word: "S.T.A.R.S.", his mission target). Even when Jill tries to make her escape via helicopter, Nemesis is smart enough to shoot the helicopter with a rocket launcher to cut off her escape.
Though not smart enough to wait for her to board the helicopter first.
Used in Resident Evil 4 to show you they're "Not Zombies", by using weaponry, setting traps, and cooperating with each other.
The Verdugo as well. If you blast it with a rocket launcher it shrugs off the explosion and tauntingly wags it's "finger" at you before resuming it's attack.
Resident Evil 6 features an evil(er) knockoff of The Nemesis with Ustanak. It's smart enough to predict where you're going and set a trap rather than just smash through the wall to keep chasing you, select and equip weapons, and even deploy small flying creatures in a search pattern to cut off your escape and track you down.
Occasionally happens in The Elder Scrolls IV: Oblivion: you think you've outsmarted a melee-only opponent by climbing on a rock where they can't get up, but then they appear behind you...
Given the typical behaviour of NPCs in Oblivion, witnessing this is downright astounding.
One of the more terrifying aspects of Penumbra: Black Plague is this trope. The dog/wolf monsters in Overture seemed to just be aggressive beasts. Your first encounter with one of the infected in Black Plague? It's looking for you with a flashlight in its hand.
The Shades from NieR. At the beginning, they seem like mindless monsters. By the end, they're using weapons and armor, and they can sucker the title character into a deadly ambush with one of the Plot Coupons.
Many Fallout 3 players learn the hard way that Deathclaws, the twelve-foot-tall bipedal reptilian killing machines, can open doors. Thankfully not represented in the game is the fact that Deathclaws can mimic voices and lure humans into ambushes with cries for help.
Redlight in Prototype seems like your typical zombie plague. In the backstory, however, is the way the first outbreak occurred: after the test subjects - a few citizens of a small town - were infected, nothing happened at all for four years until the scientists who'd expected a spectacular response packed up and let their guard down. At that point every single subject - by then the entire town - suddenly mutated and attacked all at once. The Virus had waited patiently, spreading quietly, for just such an opportunity. It only acts that way when it has a Runner to direct it, though; the rest of the time, it really is your typical zombie plague.
And of course the next iteration, Blacklight, is a fully sapient individual, obviously capable of independent thought, speech, planning, and emotions - you, the player.
In Mass Effect 1, you come to a space station which was overrun by rachni, and you can read a log where a scientist states "we treated them like beasts, should have treated them like POW's". Mind you, the race is well known to be sentient - although their appearance can certainly deceive. The theory was that without the connection to the Queen that all the warriors would become mindless beasts, in the eyes of the Queen that's that they have become, but turns out that's not quite the case.
As per the Warhammer 40000 example above, while playing the Dawn of War II: Retribution Tyranid campaign you can hear Imperial Guardsmen realizing "They're using cover! They're supposed to be just animals!" In their defense, their training manuals do insist that Tyranids are simple-minded beasts.
Dragon Age: Origins – Awakening shows this trope early on with a talking darkspawn. It turns out that these all originate from one darkspawn, called the Architect, who was born free-willed and sapient and found a way to make other darkspawn free-willed and sapient just as he is.
It's implied from the trailers that Dead Rising 3 will feature a few zombies who have slightly more intelligence than the walkers. Luckily, they don't seem very accurate with pistols.
Parodied and taken to extremes in the How It Should Have Ended video "How Jurassic Park Should Have Ended". The Velociraptor figures out how to speak, finds a weapons closet, sends an email to the protagonists, and tries to attack them with guns.
Showed up with the Diamondshell Beetles in Schlock Mercenary — we, and the mercenaries, perceive them as just big, ugly monsters, but they're actually fairly intelligent, communicate amongst themselves, figure out how to use human weaponry in a surprisingly short amount of time, and see the humans (and, in particular, Sergeant Schlock) as frightening monsters…
To be fair, even Schlock's friends think of him as some sort of monster.
The fifth episode of Generator Rex deals with a Hidden Elf Village of engineers and scientists trying to build a transmitter/receiver to communicate with the nanites. Then in the next episode, Rex tries to shut down a really, really big EVO created using nanites siphoned from his body, and the nanites try to talk to him.
The Draags from Fantastic Planet hypothesize that the humans they oppress may be intelligent, but regularly exterminate them anyway.
Predaking from Transformers Prime displays surprising intelligence for a supposed beast in all of its appearances. This culminates in "Evolution" when he responds to Starscream's latest abuse by transforming and threatening to kill Starscream. Megatron for one is very unhappy with this turn of events. He wanted a mindless beast he could control. Instead, he got a powerful, intelligent, and ambitious warrior who is a potential threat.
It is now believed that most complex life forms that aren't plants have some form of decision making mechanism and the ability to adapt to their surroundings. Current research focuses on figuring out how and to what extent each species does these things.
Jumping spiders of the Portia genus. They hunt other spiders, and will observe other spiders in their webs until they can gauge how fast they are and how they react to disturbances so that they can determine the optimal strategy to take them down. They will even observe a spider's mating display so they can imitate it and attract another spider to its doom.
Since the web vibrations they need to imitate vary from species to species, Portia memorizes different chords, and actually experiments when it encounters a species it hasn't before.
In reality, watch any well-made nature show and you will more than likely view 8 to 10 animals that fall well within this trope.
A great example would be elephants. The one way most scientists gauge self-awareness is whether or not the subject can recognize their reflection as themselves as opposed to another animal. With animals, it can be a bit tricky to determine as they can't talk. However, one test is to put a mark on the animal which the animal cannot see but will be reflected in a mirror. Elephants have demonstrated recognition of their reflection by exploring the mark on their own head, not the elephant in the mirror, using the mirror to find it. So, elephants are self aware.
Chimpanzees in particular may be even more intelligent than we generally give them credit for. Scientists studying chimps in parts of Africa which are still densely forested have recently observed them not only using tools, but actually fashioning some of their own.
Add ravens, crows and magpies to the mix - the first non-mammals confirmed to have this ability, along with rudimentary skills at using tools and cooperating to solve puzzles. A group of crows in Tokyo have figured out how to use cars to crack open nuts that they cannot open on their own. They drop the nuts into the crosswalks, wait for the cars to drive over them, then fly down and eat the interior when the traffic stops. Now, add to this that they are using the traffic lights to time this operation...
They're also capable of vividly remembering a person or location that's caused trouble. If a member of the murder is killed, they're not coming back any time soon, and in fact reroute their migratory pattern to avoid landing in that area. If they've been harassed by someone, they may start fighting back, often singling that person out when given the chance.
Keas are pretty bloody bright as well, being parrots. In fact as a whole, parrots and corvids are the brightest bird groups.
Lions are not large enough to take down giraffes on their own. But, lions in some parts of Africa have figured out that if you scare the giraffes so that they run into a road with heavy traffic, the cars will kill the giraffe for you and you can get a lot of tasty dinner rather easily. This is causing serious traffic problems in some areas.
Hyenas meanwhile have a complex, simian-like social structure. They may actually even be better at cooperating and teaching than many primate species - given a task where two animals must tug at separate ropes simultaneously to get a food reward, but only one knows the trick, the hyenas were faster than primates at teaching their buddy how to do it. This is likely because hyenas hunt together and so need a "language" for cooperating and coordinating an attack, while most primate food is fairly lazy fruit, and the most you need to be able to say to share with a friend is "Here is food."
House pets, especially dogs, have been known to seek help when their owners are in trouble.
Octopuses. If not given puzzles and toys to keep itself occupied (octopied?), an aquarium octopus will invariably occupy itself by trying to escape. Sometimes they end up in other exhibits. Sometimes they end up eating the other exhibits.
Crocodiles show a surprising amount of intelligence. They are known to be able to memorize where the best places to ambush prey are, some species have learned to steal fish from the nets of fishing boats, and it's estimated that they may be about as smart as some rodents (Which, considering how clever mice and rats can be, is pretty impressive).
It was recently found that Nile Crocodiles hunt in packs, or more accurately they are perfectly willing to use team work. Sometimes one crocodile will hold a large prey animal and let the others (who take turns and equal portions) tear at it).
Crocodiles can actually learn tricks like "stay" or "roll over" meaning they're at the same level (or little below) of intelligence as dogs. The difference comes from the fact an average croc would gladly kill and eat his trainer.
Recent studies show that constrictors (IE: Pythons, boas, and anacondas) may be more intelligent than previously thought. Research shows that these snakes actually check to make sure their prey is dead when they're constricting. Long story short, an experiment was held where the snakes would constrict a meal with a simulated heartbeat. The snakes would only stop if they were sure their prey's heart had stopped beating.
Why are Orcas so popular at aquariums? it's not only since they're big and agile. They're also arguably some of the smartest things in the ocean, often just following a fishing boat and looting the net, not to mention beaching themselves to get a snack.
Orcas have also learned how to snatch the bait fish off of longlines without getting caught in the hooks, and teach others how to do it.
One pod in Australia set up a cooperative hunting partnerships with (human) whalers in a small town. When whales migrated through the area, the orcas would begin herding them into the town's bay, while one or more orcas would head to the dock to get the attention of the humans and let them know whales were coming in, and the orcas and the humans would work together to kill the whales. At the end of the hunt, the humans allowed the orcas to eat the lips and tongues of their catch, which the humans had no use for, with the orcas leaving the blubber and baleen, which the humans wanted.
There's an old joke that there's no known cases of orcas killing humans in the wild. Orcas don't leave witnesses.
Babies and toddlers can understand complex language well before they can reproduce it. If you underestimate them just because they aren't talking yet, they will outsmart you. And you will feel stupid.
While it is debated as to how intelligent they were, dinosaurs are now believed to be much smarter than we once thought they were. For years, dinosaurs were believed to be slow-witted lumbering beasts who did little more than eat, fight, and have babies. However, over the years, we've discovered that some species (particularly small meat-eating dinosaurs) were at least intelligent enough to form complex social behaviors.
Tyrannosaurus rex was not only one of the largest predators ever to walk the earth, it was also pretty smart. Recent studies indicate that it might've been at least as intelligent as modern-day alligators or even some breeds of dog.