Having the physical characteristics of immature members of most species. Often characterized by large and watery eyes, large heads on small bodies, small noses and mouths, and high pitched voices. Often encompassing the very definition of cute, neoteny can stimulate a protective or nurturing instinct in adults which might otherwise threaten it.
Since neoteny is common in the very young, species that retain immature characteristics into their adulthood find it useful as a survival mechanism.
Many cartoon characters have evolved more neotonous features over time in order to increase their appeal. Examples: Mickey Mouse, Bugs Bunny, and anything invoving "baby" characters (i.e. Muppet Babies, Scrappy Doo, etc.)
See also super-deformed.