Sylvester Stallone

In Big Mouth, Sylvester Stallone shows up as a booming, larger-than-life vision who appears to Coach Steve during one of his more unhinged spiritual detours. He talks in gruff aphorisms, radiates gym-poster machismo, and treats whatever crisis Steve is having as an opportunity for a pep talk only he could deliver.

Nick Kroll's impression leans fully into cartoonish Stallone mumble-wisdom, and the joke works because the show never explains why he's there — he just is, dispensing motivational nonsense with total sincerity. It's a small, absurd flourish that trusts the audience to enjoy the randomness without needing logic behind it.