(hi I'm P0tat0XD and this is a roleplay account I mead for my O.C. Sasa the purple text is Sasa the green text is me explaining the lore lore explanation is at the end) 

Photo dump of my pet Uranium the forever baby pick me hippo

(forever baby animals are a fictional form of animal I came up with basically the short answer is they are any regular animal that when it's fully grown still looks like they are a baby of their species the long answer is forever baby animals are not a genetic mutation they actually are an entire branch in the evolutionary tree forever baby animals start their lives as parasites that look like tadpoles with white bird wings they are roughly the size of a penny and incorporate the DNA of the first animal they infect with their own DNA making them look like a baby version of whatever animal they infected and after the transformation they stop being parasites and can pretty much eat everything with no problems the only things they can't eat are things too big for them to swallow or too tough for them to chew which the two previous ones depend on what DNA they incorporated with their own, radioactive materials, and anything with magical properties)