Among fantastic sapient species, the small, cute races (often Hobbits or Ridiculously Cute Critters) are often given personality traits commonly associated with children - such as innocence, playfulness, curiosity, or naivete - to complement their adorable appearances. These creatures are usually sympathetic, but a rare evil or dangerous example of the trope may be a Psychopathic Manchild. These little guys are often capable of inspiring protective affection in members of the bigger races, and possibly, in the audience - although they may not need it.
Despite being an iconic short fantasy race, dwarves are more likely to be treated with an inversion of this trope and depicted as if they're all born Grumpy Old Men.
A result of Emotional Maturity Is Physical Maturity, and related to the real-life concept of neoteny. Among many domesticated animals, the adults retain more cute physical traits and more youthful behaviors (such as playfulness and sociability) than adults of their wild counterparts. See also The Cutie.
- Potemayo and Guchuko from Potemayo are small, round, big-headed and completely adorable. Potemayo may have reached physical maturity for her species (given the Bizarre Alien Biology at work, it's hard to tell), but in many respects she acts like a small child. (Guchuko is more self-sufficient, but her behavior is in some ways more reminiscent of a sapient feral cat's than a human adult's.)
- Many rookie level and almost all in-training level Digimon, appropriately called "child level" and "baby level" in Japanese, look and sometimes act very childlike, with a few exceptions like Renamon. Of course, it varies with rookies, with some like Guilmon acting like very small children and other having roughly the same level of maturity of their human child partners.
- Dragon Ball Z: Psychopathic Manchild and final Big Bad of the series Majin Buu, especially in his "fat-Buu" form, speaks in a simple childish way e.g: "Buu gonna hurt you, make you sorry," is bright pink and loves candy so much that he can shoot a laser out of his headtentacle-thing that turns people into sweets so he can eat them.
- Slime Life: Slime is naïve and trusting, never cottoning on to the fact that Darul is constantly trying to manipulate him into situations where she can hug him.
- Mort from Madagascar. Despite his childish personality, Word of God says he is actually an adult.
- Exploited by Finnick in Zootopia. He is a little fennec fox who pretends to be a cute, naive, elephant-loving child... as part of a scam. He is actually Nick's hustling partner with a deep, booming voice and confirmed by Word of God to be older than 32-year-old Nick.
- Played with and then averted in Galaxy Quest, with the rock miners. At first, they expect the cute looking aliens to be nice and friendly, particularly as they appear to tend to one of their wounded. But then they start cannibalizing the helpless alien and begin attacking the crew.
- Cute little Gizmo from Gremlins.
- Hobbits in The Hobbit and The Lord of the Rings are downplayed examples. Tolkien doesn't portray them as particularly cute, but they are small people notable for their innocence and simplicity. When Treebeard adds them to the Long List poem of all the races known to the Ents, he calls them "hungry as hunters, the Hobbit children, the laughing-folk, the little people".
- Kender in Dragonlance are small, halfling-like people known for curiosity, playfulness, kleptomania and lack of self-preservation.
- Poul Anderson's Hoka series. The Hoka are a race of teddy bear-like aliens who love playing pretend. To the extent that their hat is reenacting various human fictional and historical scenarios. (Although, considering the popularity of historical reenactment and LARPing among adult humans, one could argue that this makes them less childish than nerdy.)
- In The Railway Series and its Animated Adaptation Thomas & Friends, the smaller tank engines are usually portrayed with more childlike, playful personalities while the tender engines have more matured (if still occasionally boisterous) personalities.
- Pathfinder goblins are a rare evil example. They are big-headed, child-sized, Ugly Cute little Psychopathic Manchildren who enjoy games, songs (mostly about eating or murdering people), and running around setting things on fire. The human-sized goblinoid races, by contrast, are unpleasant in much less amusing ways.
- In the original version of Journey into Imagination, Figment, as when Dreamfinder created him, he specifically made sure to include a "dash of childish delight".
- The Lumas from the Super Mario Bros. series are playful and childlike star children. Most live on the Comet Observatory under the care of their "Mama", Rosalina. A Justified Trope since they are actually children, and turn into planets, stars and all manner of cosmic phenomena when they reach maturity.
- The Nopon from Xenoblade Chronicles 1 are cute fuzzballs mostly known for being laid-back and easy-going, and for their simplistic speech pattern. Most are okay with child-like treatment the other races tend to give them, a few take full advantage of it to get away with some questionable things, while others lament that nearly no one takes them seriously.
- The Chao of the Sonic the Hedgehog franchise are basically Tamagotchi/Pokémon Expies that the player character raises like small toddlers for races and other activities.
- Mr. Saturns in EarthBound (1994) and Mother 3 are cute, innocent, Cloudcuckoolander Waddling Heads whose dialogue is in a font inspired by a child's handwriting. However, they have technology decades ahead of ours.
- Many Mythical Pokémon like Mew, Celebi and others act this way despite having access to absurdly powerful abilities.
- The Temmies from Undertale. They're Cloud Cuckoo Landers of the highest degree, think humans are adorable and constantly try to pet them, and don't seem to understand the concept of money, the fact that you can't hatch a hard-boiled egg, or how to keep their faces from jittering away from their bodies.
- The Legend of Zelda has the Kokiri in Ocarina of Time and their descendants the Koroks in The Wind Waker and Breath of the Wild, forest-based children with playful personalities and everlasting youth.
- Much like the Gremlins example above from which they draw a lot inspiration, the Ugly Cute minions from Overlord act and speak in a childlike way.
- Invoked and subverted in Futurama. Nibbler and the rest of his kind use this to their advantage, but are more intelligent and advanced than humans (at least the ones Nibbler hangs with).
- The episode "Yo Leela Leela" has Leela encounter a diverse group of cute, brightly colored aliens called Humplings, who act like characters from a cartoon aimed at preschoolers.