Prototype is an open world action game released in 2009 by Radical Entertainment, starring Alex Mercer, a shapeshifter whose powers include blades, claws and tendril attacks. Clips of its raw combat audio have circulated for years on soundboards and in fan edits, with slowed versions becoming popular for exaggerating texture and weight. The tendril sounds remain recognisable to players because they were tied to Mercer's most distinctive powers, and creators still reuse them for body horror, superpower and monster effects outside the game.