Big Slappy refers to a viral 3D model, typically rendered in Source Filmmaker (SFM), featuring a blue humanoid character with incredibly exaggerated posterior proportions. Often associated with the Team Fortress 2 community and GMod animations, the character became a sensation on platforms like TikTok and Twitter through surreal dance videos and ironic 'thirst' posting. The name itself stems from the rhythmic sound often added to its movement in videos. Today, Big Slappy is used as a quintessential shitpost icon, representing the absurd and often crude humor of internet subcultures that thrive on 3D animation parodies.