The line comes from Rusty, Dorkly's Pokemon parody series about a hopelessly confident young trainer and his badly behaved Pikachu. Headbutt is a long-standing Normal type move in the Pokemon games, where trainers call attacks by name during turn based battles, a format the anime also popularised. Short command clips like this spread on soundboards because the phrasing works without context, letting creators label any sudden charge or collision as an official attack. Its humour depends on that contrast between formal battle language and clumsy results.