A category of furry that focuses on a person who views herself/himself as a toddler aged animal. Unlike babyfurs, cubfurs view themselves as an older version out of diapers and baby like behavior, but still are at a young age. Some cubfurs may have some form of diaper, like training pants or have few baby items like blankets or pacifiers.
Childish, training pants, fursuit, yep, their a cubfur.