Nocturnal Mooks, naturally, only appear in the dark of night. Often several stages deadlier than their daytime brethren, the darkness surrounding the hero adds to the problem as they attempt to locate and slay the foul beasts within.
Often added to improve tension and attentiveness of the viewer.
- I Am Legend: The vampires qualify as this to Neville, the "hero". While he is himself a sort of inversion from the vampires' perspective; moving about during the daytime with ease to gather supplies and other necessary items, resetting traps and such for the vampires to fall into during the night.
- In J. R. R. Tolkien's Middle-earth novels, the orcs, trolls and other assorted evil creatures operate mostly at night, partly because they can see in the dark while their victims can't, but largely because most of them are weakened by direct sunlight.
- Sauron spread a sorcerous cloud to allow his armies to fight at Gondor, and its early dispersal played a large part in the rout. Although the weakness to sunlight was mentioned in the film version, the battle happened in full daylight from beginning to end.
- The sunlight is supposed to be blocked in those scenes, but you can only tell by looking at the smoke-covered sky. Otherwise it's just as light as during the day.
- "What a horrible night to have a curse."
- The Witcher loves this trope. The vast majority of monsters will refuse to show themselves in daylight, to the point that most areas in the day are classified as "safe" zones, with visitable vendors, shops, inns and townspeople. At night all citizens but Geralt and the guards (if any) are locked up inside their homes and inns as beasts roam the countryside/city, attacking all those who are in their way.
- For example, the first chapter in the game has Geralt visiting the outskirts of Vizima, arriving during the night only to be attacked by a pack of barghests. Continuing, Geralt can be attacked by Ghouls, Drowners and The Beast, none of which appear during the daytime.
- In later acts, he makes many trips through the Swamp Cemetery, where this trope is somewhat averted; the place is dangerous even during daytime, but at night you can't walk two feet without tripping over a monster.
- The Legend of Zelda has many types of enemies that only come out at night, but the ones that come out during the day are to be no less annoying.
- The Stalchildren of Hyrule Field from The Legend of Zelda: Ocarina of Time are your first introduction to just how Nightmare Fuel-packed the game is going to be. Especially after how cheerful the game has mostly been so far. After an adventure in a village of magic children and their living tree, you go outside the village to quest. Pretty field! Dainty music! Killer pineapples of doom! ...okay, maybe not safe, but even the monsters look festive! And then it gets dusk. And then the music stops. And then...they come. Skeletons from the ground, able to appear no matter where you run. Kill them, more pop up. Kill more...a GIANT one pops up.
- Certain beasts only show up at night in The Legend of Zelda: Twilight Princess as well. And who could forget the effects of Twilight itself?
- Psychonauts has certain beasts appear in the real world when it is nighttime - particularly noticeable are the giant red-eyed bears which hunt Raz and populate the forest areas.
- The Telekinetic Bears are actually there day-round, although they stay off the beaten track. However nighttime adds Pyrokinetic Cougars to the mix, who like to stake out previously safe zones.
- In the Quest for Glory games, wandering around at night is suicide at the beginning. However, once you gain enough experience, the nocturnal mooks start showing up during the day as well.
- In Dead Rising, the zombies get glowing eyes and a large number increase at night. Good times.
- The Imps in Rule of Rose are usually accompanied by darkness. They are mostly met in the badly lit parts of the airship, and when the power goes down they start appearing almost everywhere. Likewise, in the final chapter orphanage there's no fear of enemies until the sun goes down. After that, you can't spit without hitting an Imp.
- Played With in Pikmin. One of the common enemies is only active at night (unless provoked), but you only have a chance to fight it in the daytime when it's asleep, as you leave the planet every night.
- Dragon Quest uses this in a lot of games from 3 on.
- From gen-2 on, Pokémon uses this. In real time. Gotta Catch 'Em All? Gotta stay up for hours past your bedtime!
- Final Fantasy XII uses something mechanically similar, but using the flavor of weather conditions. Many mooks will only attack you if the weather's right.
- In Minecraft, Most Mooks only come out at night or in dark caves, and burn or turn passive in sunlight. It's made Worse by the fact that the game completely averts Hollywood Darkness. Notably though, Creepers are completely unaffected by sunlight and will attack you during the day.
- Fungi Forest from Donkey Kong 64 has certain enemies, like skeletal Kremlings, that only appear at night, to replace daytime-exclusive enemies.
- In Mother 3, the enemies in the graveyard only appear at night. Since the time of day is driven by the plot in this game, you only get these enemies at pre-determined points in the game, most notably the beginning of Chapter 2. Likewise, Mr. Batty will only appear in the Sunshine Forest at night.
- Terraria, most of the dangerous things come out at night, at least before you reach Hardmode. Also, many bosses can only be fought at night (and some of them will gain the ability to instakill you if you don't kill them by dawn.