Nearly any modern portrayal of Mori Ranmaru falls heavily into this if you aren't already aware of the historical figure. Historical artwork of him is a bit better.
Recent artwork of Hindu gods or goddesses tends to portray them all as quite Bishōnen. This is only partly true for historical depictions; while male figures were still drawn or sculpted as lithe, slender, and smooth-skinned, the secondary sexual characteristics of females were... much less ambiguous.
Renaissance- era depictions of The Beloved Disciple (John) and sometimes even John the Baptist (!) show beardless pretty boys who could be taken for girls. This is probably the reason for the well-known claim that Mary Magdalene appears in Leonardo's Last Supper.
Krazy Kat never displayed a specific gender trait of any type, but was in an ongoing love triangle of sorts between two identifiably male characters.
While Siobhan from Anya's Ghost does have a feminine name, it's a very obscure Irish one, and she dresses in a male school uniform, complete with necktie, for the entire story. She isn't even referred to with female pronouns until well past the halfway point of the book.
Xarcce Huwla of the X-Wing Series is an alien Tunroth, making her big, muscular, and with a very inhuman face. Since these comics were drawn with minimal concern for Fanservice, even when sparring in tight clothing◊ her body is easily taken for male, and since she's largely out of focus pronouns only come up a few times.
The protagonist Tykvenkom of the 1984 Soyuzmultfilm short cartoon And what can you do? (а что ты умеешь?) is a pumpkin with visible eyelashes, a flower in its head ( Later losts it after it got growned to save the animals, but was given more flowers in its head at the end), and was voiced by veteran voice actress Clara Rumtanova, yet official descriptions of the cartoon refers Tykvenkom as a male.
In The Many Adventures of Winnie the Pooh and every other animated Pooh adaptation afterwards, Piglet. He has a very high shrill voice (a man, John Fiedler) in America, but foreign dubs have cast female voice actors for his role several times, adding to the confusion.
Old Soviet Piglet was a charming old grannie VA who circa 2007 claimed on national TV to support herself in retirement by voicing lulzy gag dubs of german hardcore porn... But her Piglet is a wimpy boy voice. And the sample of porn voices she did, for multiple orgy participants afair, could blow your mind! (still not 100% she wasn't messing with the audience, though)
One of the strangest examples is the title character of The Brave Little Toaster. Fans are pretty evenly split between "the Toaster is male" and "the Toaster is female". You never hear anyone referring to Toaster by a pronoun (except for a single line of dialogue — yelled over a roaring waterfall) and Toaster's personality is fairly gender-neutral, unlike any of the other characters. And thanks to Cross-Dressing Voices, the fact that Toaster's voiced by a female is no help. And we're still talking about a machine.
The toaster is the perfect example of a gender-neutral character. The voice acting, dialogue, (most of) the pronoun references, actions, attitudes, fears, thoughts, character development, none of that suggests any particular gender, but it doesn't suggest It's Pat-style androgyny or a robot either. With Slippy Toad the demeanor and voiceover begs the question, but the only reason you'd consider the toaster's gender is if you think about it years after watching, or if someone else brings up the question.
In the book, not only is the toaster explicitly without gender, this is something of a plot point when the group encounters a mated pair of squirrels that cannot conceive of a genderless being. The toaster ultimately convinces both of them separately that it is the same gender as they (male for the male and female for the female) — but really it's just to spare their feelings.
In Bambi, who really can be mistaken for female is Flower, the skunk. When he is a child, his voice and speech patterns sound nothing like a male, he acts shy and bashful, is very fluffy, and spends much of his time smelling flowers. A couple years after his introduction, when Bambi meets him again, his voice has deepened and he gets an only slightly more effeminate girlfriend.
There is the picture book of the Disney movie that actually called Flower a female, and made "her" amother!
The makers of Monsters VS Aliens themselves seem to be confused over the gender of Insectosaurus. A behind-the-scenes book labels the creature as a "she" while, within the canon of the actual film, the monster is a "he".
The twin dolls 3 and 4 in 9 look completely identical (save for their stamped-on numbers), act alike, and never speak, making it completely ambiguous as to what gender either of them is. This is compounded by the fact that, as living ragdolls, they don't have any external characteristics indicative of sex. The creator has urged fans to come up with their own theories regarding the two.
In the Chinese animated film Nezha Conquers the Dragon King (1979), the title character is a little boy but he looks and acts more like a little girl — the hair style, clothing, and voice don't help either.
The starfish, Peach, in Finding Nemo. Its voice actor is a woman, but her voice is just masculine enough to make it sound like a guy. Conceivably intentional, as some varieties of starfish are hermaphroditic.
Tarzan: Anybody else have to be reminded that the gorilla Terk (voiced by Rosie O'Donnell) is female?
A large number of viewers of trailers for Kung Fu Panda, who were unaware of just whom Angelina Jolie had been cast as, were in for a shock when they finally saw the film and Master Tigress spoke for the first time. In everyone's defense, not only did the lack of Tertiary Sexual Characteristics make it very hard to tell her gender, even her voice actress originally assumed, when the casting call was made public, that Jackie Chan would be playing the tiger. This confusion only added to the Stupid Sexy Flanders associated with the character (although for some viewers it didn't lessen the appeal).
Two of the background race cars from Cars: According to their toy bios, the pink race car sponsoring Tank Coat is actually male, and the blue race car sponsoring Rev N Go is actually female.
Laverne, one of Quasimodo's gargoyle friends is apparently female (as far as stone can have a gender).
Remember the alligator from All Dogs Go to Heaven? You always thought it was a female, right? WRONG. It's male.
It doesn't help that he's never mentioned by name in the film (Only in tie-in materials). Otherwise, the fact that his name is King Gator would be a huge hint to his gender. His singing voice is also very masculine, but could be heard as a deep female voice too.
Rolly from 101 Dalmatians. In the animated series and his cameo in House of Mouse, he's been given a blue collar. Only female puppies were blue, the boys all wear red. Oddly he's the only male to be given a blue collar and he's still clearly referred to as male.
The Incredibles has Edna Mode, or "E", who first-time viewers sometimes mistake for a guy. This can mostly be attributed to her not having the traditional Tertiary Sexual Characteristics, or a noticeable figure; not to mention being voiced by the film's director, Brad Bird, for extra androgynous points.
Cupcake from Rise of the Guardians. She wears pink clothes and a skirt, and is obsessed with horses and unicorns, but looks more like a boy than a girl, and can easily be mistaken for one.
Rancis Fluggerbutter from Wreck-It Ralph. He's one of the few boys among the Sugar Rush racers, his hair is long enough to be mistaken for a girl's pixie cut, and his name is based off of the name Francis, which is a boy's name, but which sounds identical to the name Frances, which is a girl's name.
He regurgitates some food for the main character Hiccup like a mother bird.
In a scene where he looks at a bird's nest, the intention was to show how Toothless wanted to fly, but the camera lingered on the eggs for a bit too long, so it seemed like Toothless wanted to get back to his own eggs rather than wanting to fly.
The way he holds onto Hiccup at the climax of the film resembles a mother and her newborn child.
Destoroyah from the Godzilla franchise is officially a male Kaiju. However, that hasn't stopped fans from thinking he's a female because some aspects of his body structure are similar to that of female crabs.
And, then there's also Mothra Leo from the Mothra Film Trilogy. For the record, Leo is a boy. Yes, you heard me. A Male Mothra. (Mothrus?)
Even the dub of the films had trouble with this and constantly referred to Leo as both a "he" and a "she" and even an "it".
An interesting variation of this occurs with the monster Rodan. In the original 1956 film Rodan, both a male and a female Rodan are featured. Since then, fans have argued whether or not the Rodans(?) featured in later films are male or female.
Some people have mistaken Gigan, a male cyborg kaiju, for a female due to his high-pitched roar.
Battra, Mothra's Evil Twin, has also been mistaken for a female.
And it doesn't end there, with Kroiga from Latitude Zero. With the brain of a human female, but the body of a male lion.
Kumonga has been mistaken to be a female by the fandom. This is due to the dub of Son Of Godzilla not using any gender-specific pronouns regarding the giant spider. The original Japanese dub, on the other hand, refers to the monster as a male.
Kamacuras is also officially a male, but fans often mistake him for a female. However, since there's more than one Kamacuras, it could be possible at least one or more of them is a girl.
Godzilla himself, sort of. See, suit actor Haruo Nakajima believes that the Showa Era (1955-1975) Godzilla is a female while the original 1954 monster was a male. However, Toho Studios has stated that all the incarnations of Godzilla that we've seen are male. Considering that the films establish that there is more than one Godzilla, and that infants like Minilla and Junior show that there's a breeding population, the idea of a female Godzilla isn't that far fetched. It's just that we haven't officially seen a lady Godzilla yet.
There are people out there who think the Newborn from Alien: Resurrection is a female. For the record, it's a hermaphrodite. The actual prop used for the film had both male and female genitalia. This actually applies to all members of the Xenomorph species, even the Queen. H.R. Giger intended the Aliens to be neither male nor female, but an unsettling blur of both sexes.
Some viewers of The Year Of Living Dangerously were surprised to learn that Billy Kwan was played by a woman, Linda Hunt. She's the only actor to receive an Academy Award for playing a character of a different sex.
Jodie Foster's daughter in Panic Room (played by the then 11-year old Kristen Stewart) has a fairly gender neutral haircut, somewhat androgynous looks and wears uni-sex pyjamas and can easily be mistaken for a boy on first viewing.
In I Am Legend, Sam the German shepherd isn't revealed to be female until she gets hurt, at which point Will Smith calls her by her full name of Samantha.
The daughter Marley is this for some viewers. Whenever we see her she has a fairly short hairstyle and gender neutral clothes. It isn't actually said whether or not she's a girl until about an hour into the film.
Vidocq intentionally leaves the true sex of the Alchemist vague for most of the film. The character is covered in loose black robes and wears a head-covering mask. The letters written by the Alchemist vary from demonic threats to feminine coyness, and the character's shrill, metallic voice sometimes has a distinctly feminine edge, especially the moans in some battle sequences. All these are Red Herrings. The Alchemist is male.
In Heroic Trio, the Big Bad looks like an effeminate male but has a female voice. This confusion might only be thr Western audiences who might not be as familiar with Chinese legends concerning eunuchs making for extremely powerful soldiers while simultaneously making them evil and manipulative.
That's because initially the character *was* a girl, played by Matthew (Stymie) Beard's real-life sister Carlena. Even after male actor Billie Thomas inherited the role, the character continued to be portrayed as a girl for several shorts.
Alexa in 50 First Dates, which is intentional on the part of the movie.
Robin Williams' daughter in What Dreams May Come is very androgynous, and it's perfectly possible to go through most of the movie thinking she's a boy.
Dennis, the kid who wanted pancakes, from Cabin Fever. He has very long hair, a somewhat feminine face, has a gender neutral voice, and is prepubescent from the looks of it.
Angel from Rent has some of this, but it's not due to androgyny .It's more like Ambiguous Gender Identity, since they are biologically male, dating a gay man, wear women's clothes, usually get called she, and at least one character is unsure what pronoun to call them by. Interpretions vary between crossdresser, M-t-F transsexual, Drag Queen, genderqueer, and everything else.
Quite a few people who hadn't read the source material of The NeverEnding Story mistook the warrior Atreyu to be a girl.
In Hungarian, pronouns aren't gender based, leading generations of The Lord of the Rings readers thinking that the Witch-King was killed by Merry, not Éowyn. And coincidentally, neither the appendices nor the prophecy (No man shall kill him — it was a Hobbit!) contradicts this. But it's clear in the original.
For a long time, half of the Harry Potter fandom thought Blaise Zabini was a girl, since he's just a name until book 6. (Specifically, a name which is masculine in Europe but usually feminine in the United States.) Some who wanted more Slytherin girls used "her" extensively as an OC Stand In in Fan Fic. It's now known that "she's" a he.
If you're well-informed enough to know that the Groke of the Moomin series is female, try figuring out Thingumy and Bob, or the Fillyjonk's children from the anime. Too-ticky can also be misleading because of her appearance, but it's pretty clear she's a woman.
Too-ticky is at least partly based on Jansson's sculptor girlfriend, which may account for her relative butchness.
In the original Swedish, the Groke is called Mårran which manages to sound both feminine and threatening.
Thingummy and Bob wear dresses, and in the original are named Tofslan and Vifslan — so there is no "Bob" to confuse people. (Their particular way of speaking is an in-joke on the lingo Jansson and a female friend used. "Tove" becomes "Tofslan" when you speak like that...)
Actually, that "female friend" was her first girlfriend, Vivica Bandler. The whole plot about the Ruby and the Groke is a metaphor for them having to hide their relationship back in the days homosexuality was still a crime and taboo in Finland.
A milder form of this occurs in Honor Harrington. The Royal Manticoran Navy has nearly 50-50 gender equality, and many characters are referred to as their title, i.e. Admiral, Captain, Exec., etc. To compound this, many of the women are given masculine nicknames, like Michelle becoming "Mike", while some men are given female nicknames, such as a Gervais becoming "Gwen". You may need to take notes.
Possibly compounding the issue is the fact - never explicitly stated - that almost any character, when talking about someone of unknown gender, will use their own pronoun (i.e., men call unknowns "he" while women call them "she").
Maybe more of Translator's Gender Confusion, but in Polish translation (where gender pronouns are everywhere) Patricia Givens was men for two books because she was always referred to as "admiral Givens" or "Pat".
Max, from the Maximum Ride series. Considering that the book is written entirely in first person and her masculine name, it's no wonder. It's not clear at all that she's female until at least about fifty pages into the first novel, when she is finally referred to with a female pronoun.
Discworld dwarfs. Most of them look male, but that doesn't mean they are.
This is expanded upon with Cherri Littlebottom, a feminist in a race where discovering the other's gender is part of the mating ritual. She would wear makeup, but refused to shave her beard because to do so would deny being a dwarf.
In the kid's magazine Muse, four New Muses are guys, four New Muses are girls...and nobody can agree what gender Egyptian-born Pwt (pronounced "pwit" is. Word of God confirmed that Pwt is a male, but some readers still think he's a girl.
In Goblin Moon, the anthropomorphized Nine Seasons are the setting's equivalent of gods. Four are male, four are female, and one (corresponding to mid-spring, a changeable season) is depicted as androgynous in religious art.
The first two chapters of To Kill a Mockingbird leave Scout's gender very much in question. (She's a girl.)
The Timothy Zahn novella Cascade Point is told in the first person, and the narrator's name is not gendered. Only the cover art assigns a gender.
In the graphic novel Level Up, one of the angels (the one with orange hair) appears to be a girl, but when she reveals her true form as a Pac-Man ghost and Dennis eats her, she is referred to with male pronouns. However, he/she may have No Biological Sex due to being not a human ghost, but an Anthropomorphic Personification of a broken promise Dennis's father made to his dad.
The Cherub in L. Frank Baum's John Dough and the Cherub. The publishers wanted the author to end the confusion, so he agreed to a write-in a contest. Since the first two winners chose differently, the gender of the Cherub remains unknown.
Zom-B by Darren Shan: One of the two big twists at the end of the first book is that main character B Smith is a girl. The book had done a damn good job of leading the reader to believe otherwise, from the fact that most of B's friends are boys to the illustrations always showing her from behind (with a slim build and shaved head.)
Of course, Spot also changes breeds a few times, so changing gender was probably all in a day's work.
One fan theory is that Data had multiple cats over the years and Data being Data, named them all Spot.
Another fan theory is that these changes are the result of recurring transporter accidents that they never bothered to fix.
X-Play had a segment called "Guy or Girl", where the viewers were asked if some androgynous video game characters were either male or female. It was later re-used as "Robot or Human."
Grace Polk from Joan of Arcadia, although it was addressed in the first episode when the character got mistaken for a "very rude boy" by another character.
George from the British kids TV show Rainbow. Despite being pink with long eyelashes, having an effeminate voice and being the girly one of the group ("ooh, you are naughty!"), the character was male. The name should have been a clue, but the hugely popular kiddie book series The Famous Five did feature a girl called George, as does the Nancy Drew series...
Snoop from The Wire confused a lot of viewers. She dresses exactly like the men, hides her braided hair under baseball caps, makes suggestive comments about other women, has a very gravely voice, and generally makes her way as a stone killer in a man's world. The only time she wears feminine clothes in the entire series, she's also wearing a face-convering motorcycle helmet on a drive-by shooting. Marlo's first words to her are, "Your turn, girl", however, so the series is never trying to deliberately confuse the audience.
Alpha Centauri, in the classic series Doctor Who serial "The Curse of Peladon" (and "The Monster of Peladon", its sequel). A bit different, given its not even vaguely human. But both stories generally depict it as being female.... it doesn't help that the voice and body mannerisms are all very definitely feminine.... when, in actual fact, its an "it" (it has no specific gender). Further viewer confusion is gained by nearly every character refering to it as either "he" or "him", despite the visual and aural indicators being for the opposite.
Though it's quickly apparent if you watch the show, many people who hear of Angel assume it stars a woman, thanks to his Gender-Blender Name. (The show Dark Angel probably didn't help.) Lampshaded by Cordelia in Season 2 when She says "She could have been Angel because its kind of a Girly name"
He used to go by the name of Angelus, which is clearly masculine.
He's also a vampire, just to make the name more confusing.
Though this is on purpose he is quite deliberately the demon with the face of an angel.
The funny thing about "Angel" being a Gender-Blender Name for a man is that all the angels mentioned as having any sort of gender in The Bible are male.
Also Angel (pronounced "ON-hel") is a fairly common men's name in Spanish-speaking cultures. One notable (and quite masculine) example is Angel Batista from Dexter, who's of Cuban descent.
The title character of Skippy The Bush Kangaroo was female — people tend to mistakenly refer to her as a "he" (then again, Skippy is nowadays primarily known through Popcultural Osmosis). Major clue that Skippy is a girl: she has a pouch.
Uni Sax from Super Hero Christmas. Even in the illustrations that accompanied the credits, she could be either or. Then again, this is largely justified, considering her goal was to make everyone look and seem the same, which includes having nothing to define who or what you are.
Coach Bieste from Glee. Many viewers believed, or still believe, she is played by a male actor. (She is, in fact, played by Dot Jones.)
And then there's Kurt. The combination of his very high-pitched voice, Camp Gay mannerisms, elaborate outfits, and Bishōnen, sometimes outright feminine appearance make it easy to mistake him for a girl at first, or at least a Bifauxnen. The actor's going through puberty helped to alleviate this... somewhat.
Saturday Night Live: The "Pat" sketches star a person of indeterminate gender who causes confusion to everyone around them by not telling anyone what gender they are, causing much awkwardness (and hilarity).
Perry in "Kevin and Perry" is played by a woman.
Toripter from Engine Sentai Go-Onger caused some confusion around the gender. It wasn't until later in the series that Toripter was revealed to be male (albeit a CHICKEN, having a female VA and sounding somewhere between a teenage boy and an older lady)
Raenef and Erutis of Demon Diary look like a girl and a guy, respectively. But, of course, it's actually the other way around. Raenef falls victim (rather literally, actually) to Dude Looks Like a Lady at one point, and Erutis rants at the artist for making her look so boyish that the readers get confused.
Victoria Lengrand from Beach House has been mistaken for a man on multiple occasions due to the tone of her voice.
Taylor Hanson from the teen pop group Hanson: ambiguously pitched voice, long hair, and gender-neutral name.
Kalan Porter from Canadian Idol definitely confused many people.
Pick a J-rock band. Particularly male jrockers that dress in Goth Loli, like Mana.
Pick any J-Pop boy band, especially those under Johnny's Jimusho. Those guys make prettier girls than most of their fans.
Visual Kei musicians can easily cause this problem, as a common theme amoungst the bands is to highlight their feminine sides or just full-on crossdress like Hizaki◊ from Versailles.
Back when the Culture Club was all new, a good few people assumed Boy George was female.
Similarly, during one of the episodes of I Love the 80's, when discussing the Dead or Alive video "You Spin Me Round", one of the commentators said that growing up he thought Pete Burns was either the prettiest man or the ugliest woman he'd ever seen.
Many were surprised to find out that Noodle of Gorillaz was a girl. Less so once she started being depicted as a teenager who sometimes sports makeup and more feminine clothing, though she still leaves a few confused.
Tracy Chapman. Judging by her voice, rather muscular physique, and most pictures, it can be pretty tricky to tell. Her gender-neutral name doesn't help.
The lead singer of Placebo, Brian Molko, has confused many with his highly effeminate appearance. Pictures like this◊ and this◊ definitely do not help.
An anecdote from the early days of ABBA relates how Bjorn Ulvaeus initially got a number of letters from fans who thought he was female. The explanation he gave was that the letters had come from Eastern European countries, where photo quality broke down through multiple copying, leaving his defining characteristics as his androgynous clothing and long hair. But it probably didn't help that he dressed more effeminately than Benny usually did, either...
Amber from the Korean pop band f(x) to the point where her group members even thought she was a boy at first. It doesn't help that she's "pretty" enough to look like most male pop stars or that SM Entertainment always puts her in masculine clothing, such as a boy's school uniform or a male hanbok.
Michael Jagmin◊ of A Skylit Drive tends to have this effect on people: long hair, girly voice, short stature.
Japanese goth/electronic/visual kei/oh who knows vocalist Selia (one half of Seileen, along with DJ Sisen) falls into this all too easily. He looks like a woman, but in Japanese music this isn't anything new. No, the real confusion comes when he starts singing.
The same goes for Arch Enemy vocalist Angela Gossow, who's death vocals cause many to mistake her for a man at first listen.
The Silversun Pickups's lead vocalist Brian Aubert has a somewhat effeminate voice when singing, leading to some confusion—especially since even when you know he is a guy he looks nothing like you'd expect for a guy with that singing voice. His speaking voice is unquestionably male, though.
Justin Bieber. He's made his career over the fact that he's a teenage boy whose voice hasn't cracked, so this is a given. If you just listen to his music and don't know his name, you might think he's a lesbian. The amount of Viewer Gender Confusion has become memetic due to his Hatedom.
There are a lot of K-Pop idols that fall under this. Super Junior's Heechul◊ and Shinee's Taemin◊ are two of the worst offenders. Even the more masculine ones are prone to this... Shinee's Minho◊ was once mistaken for a labelmate's girlfriend.
JD Samson of Le Tigre. An out lesbian who identifies as female, she nonetheless uses a very macho variation of her given name (Jocelyn Samson), dresses in traditional male clothes, maintains an extremely masculine appearance, and proudly sports close-cropped hair and a robust natural mustache. Even when you know she's a gal, seeing◊ pictures◊ like◊ these◊ makes it pretty tough to grasp.
Shelly West (daughter of Dottie West) has a rather low, rough voice for a female, particularly on her Signature Song "José Cuervo". If you didn't know the artist's name, you'd certainly be forgiven for thinking a man sang that song.
Rocker Aldo Nova's voice can easily be mistaken for a woman's in his hit single "Fantasy."
Most people who listen to Studio Killers "All Men Are Pigs" assume it's sung by a woman but when the lyrics say "all men but me" they assume it's either satire or the song is sung from a male perspective. The actual singer is a man.
Steve Marriott (Small Faces, Humble Pie) had a high-pitched voice that could sound a bit womanly at times, which combined with his boyish face probably threw some people off (that might explain why he had a mustache for a while).
The Dutch version of Sesame Street features a blue Big Bird called Pino, who started out being played by a man. When he retired a woman got the role, there was actually some debate among the creators about whether they should make the bird a pink girl and rename her Pina. In the end they chose gender confusion over gender bending.
The German version once got a snail called "Fienchen" note "chen" is a German diminutive — i.e. literally means little/small, can be used in nicknames as an expression of endearment. Fienchen started out being male, but due to his "cute" name and high pitched voice, he caused so much gender confusion, they actually changed him into a girl.
That's the one case where gender confusion would be appropriate. Snails are hermaphrodites.
BIONICLE. Period. The toys have little room for Tertiary Sexual Characteristics due to their modular nature (it is a LEGO product line), so the only reliable way to pick out which one is the girl is the series' color-coding (the blue ones - at least the blue heroes - were the girls). Same thing in-story, but at least the characters can use voice and body language to tell genders apart. Roodaka, despite wearing black instead of blue, is the only woman with an actual feminine figure - but we've never seen males of her race, so for all we know they cause confusion in the other direction.
Actually, we have seen males — they looked exactly like her! The comic colorist tried to color-code the male by painting him green, but Word of God says that picture is non-canon, and all of the members of Roodaka's species (the Vortixx) have the exact same colors. Yes, even the males have huge breast-plates, wide hips, a ponytail, walk around in high-heeled boots, and not one of them has any variation in their coloring. The only way you can identify the genders is that if you see a Vortixx suffering or doing some incredibly tedious and tiring work, it's a male.
Things wouldn't be so difficult if the female sets had been designed to look the part. Jaller Inika, for instance, was the manly leader of his group, yet he was the only one who looked at least a bit feminine — the real girl, Hahli, received a huge chin, a bald head, and a mustache and goatee in the form of breathing tubes! The Inika were of course a Deconstruction of certain Toa-related tropes, but only in the story. Sets could have followed a more conventional approach. Although there is nothing to suggest this wasn't the result of test groups' dissatisfaction with female-looking toys.
Hahli's infamous tube-stache wasn't the first instance of a female character receiving a misleading mask. There was Macku, who had this long, pharaoh-beard like structure on the underside of her mask. The first movie redesigned that mask-type so that it would have a mechanical "beard". Macku's movie-mask got a shortened version, but it still looked off.
Arguably The least feminine of them would be Gali Nuva◊ Thats right, the one with dual battleaxes, wide chin and ahnold pecs is the female.
This◊ is Gali Nuva again, in her Adaptive Armor. With her flat chest, wide shoulders, gorilla-arms, hunched posture, and broad, protruding chin, bald head, waffle-eye and jet-wing ears(?), not only does she look even less feminine than her "base" Nuva form, she doesn't quite look like anything else seen in the story. As a result, it's one of the most unpopular figures of the franchise, and perhaps the main reason why the "Mistika" set-line got such an unfavorable fan-reception.
One prime example was with the "Mistika" characters, as Word of God had said one of the three Makuta in the set was to be female, and since none of those three were blue the color code wasn't going to be any help. When the fanbase got pictures, many guessed it was Krika, a sleek white character with a feminine-ish name and an elongated head/mask reminiscent of a ponytail. It turned out that the female was actually Gorast; a short, squat, green-and-black hag with four arms.
And did we mention that when the series got ReTooled with a new setting, the color code ceased to apply to gender? (The girl is still blue, but there's also a male blue character.)
But at least that one single female character was designed to actually have some feminine physical characteristics, like a slender body, and... wait, that was it.
There are some subtle hints sometimes though, such as Nokama Metru's smoother mask design, Hahli Mahri's sleeker mask and her angel wings, and Gali Mata's inverted legs and extra chest-piece. But that's as helpful as it can go.
When the original line first hit, there was next to no supplementary material to educate buyers on which gender the characters were, but thankfully the narrator on the early promotional CDs, which only saw a limited release, made a point of referring to Gali by using female pronouns as many times as possible. On the other hand, he did call Nokama, the only other female set sold at that point, a "he", thus muddling up the then-introduced "blue=girl" rule.
BIONICLE's successor Hero Factory has Breez, who is female despite looking just as manly as the others.
It helps that her full name is Natalie Breez, though others mostly just call her Breez anyway. As for her looks, her helmet's eye-holes at least looked feminine at first. Then, she switched them to a generic design, along with adapting this huge, manly chin underneath.
The sheer number of occasions that LEGO and associates mistakenly or by necessity made men out of their women is enough to confuse every outsider. Besides the thing with Nokama on the promo CD mentioned above, Hahli also got a male voice in the online Toa Mahri mini-movie and in the video game BIONICLE Heroes (Roodaka, perhaps the only obvious female toy of the franchise, also received generic male grunts in that game), the Voya Nui On-Line Game referred to Dalu as a "he" at one point, and more recently, the web bio of Hero Factory's Natalie Breez also used masculine pronouns. Then, there are the Direct-to-Video movies, which gave random background Ga-Matoran (all female) male voices.
The Beanie Baby Erin. Paired up with the Princess Diana bear. Green, as opposed to Diana's more feminine purple. Especially if you were unaware of the differences between Aaron and Erin (phonetically identical) as a child.
The toyline-only character Sonar from Beast Wars is considered female by some fans due to the lack of gender-specific pronouns on the toy's bio.
Confirmed in the comics, which took advantage of the lack of pronouns to add another female to the ranks.
Kid Katydid from The Bug Pond is often mistaken for a male by first time readers.
In some cases, Eldwin is confused for female.
One of the quote on top of the page comes from the Rifftrax of Jurassic Park. Weird Al repeatedly stops commenting what's actually going on in the movie to ponder what is the gender of the kid seen at the beginning of the movie (the one Grant threatens with a Raptor claw).
Heyoka, of the Whateley Universe. Heyoka used to be a girl before manifesting as a mutant who can change shape when absorbing a spirit and its power. Normally very attractive and very androgynous, Heyoka has looked very feminine, and very masculine, at different times. even the authors have trouble with the pronouns.
In The Nostalgia Critic review of "Nickcoms", he plays a game called "Boy or Girl" with the kids from You Can't Do That On Television.
Minky Steve from Parsley Boobs. He/she is either a slightly masculine-looking woman or a very Camp Gay man.
In The Guild, Bladezz's adolescent sister has long hair, but it just makes her look even more like her brother. She has a husky voice for a girl and is first seen wearing a baseball cap and rather gender-neutral clothing.
Flaky from Happy Tree Friends is thought to be a boy because, unlike Giggles and Petunia, Flaky doesn't have eyelashes but is given a distinct feminine voice, it shows neutral characteristics for any gender but the voice actor suggests female, even the creators are undecided. It's even lampshaded a few times.
Cuddles can even be mistaken for female by some who are watching the show for the first time.
Youtube comments on newer Baman Piderman episodes frequently ask if Pumkin is a girl, perhaps due to his cute, awkward nature ever since gaining a body and his actions towards Piderman, despite him being unambiguously referred to as male In-Universe.