A Pup is a person who takes on a young-dog persona in a consensual context, typically expressed through gear such as a Pup Hood and Pup Mitts, playful posture and behaviour, and interactions with a Handler and often a wider Pack. Pup identity ranges from a scene role assumed occasionally to a lasting facet of self expressed regularly within Puppy Play communities.

The modern Pup identity emerged with the crystallisation of Puppy Play as a distinct Leather subculture in the late twentieth and early twenty-first centuries.

Communities differ on how Pup identity relates to gender, sexuality and adjacent traditions such as Wolf Play or Fantasy Animal Play. The Lexicon records the term as widely recognised across many expressions.