Context: This is usually played as a theatre student or children’s game and is chanted while alternating between clapping your hands and slapping your thighs.

A.F. : It’s called Thumper, which—
P.Z. : Thumper?
A.F. : Which, it is played two ways, like the main two
P.Z. : Okay
A.F. : So it’s like “Thumper, thumper, this is how you play, one, two, three, four,” and then you can say like, say we can play the name way. So like “[name], [name], [collector’s name], [collector’s name], and then when it’s passed to you you have to say “[collector’s name], [collector’s name],” then someone else’s name and if you mess up then you’re out.
P.Z. : So if you mess up, as in..?
A.F. : Like, you’re off beat, or you forgot to say a name, so say if I say “[name], [name],” then I forget to say the next name then I’d be out
P.Z. : Okay, so you want to be the last person?
A.F. : Yeah. And then the other ways you can play are like, you’re an animal, or have a sign, like you can be like, a llama, a narwhal, a unicorn, like, you have to do your sign and then the other person’s animal. So that’s the two ways we typically would play.
P.Z. : And there’s two versions of that one?
A.F. : Yeah, one about names and—
P.Z. : And was that another camp game, or..?
A.F. : Thumper’s just a childhood game.
P.Z. : Childhood? Like elementary school?
A.F. : Yeah, I’d say elementary/middle school

Thoughts: I’ve heard of numerous theatre-style games from my friends who are acting majors or simply took an acting class. Some other examples include the game Zip Zap Zop. It seems the purpose of these games, traditionally played with children from elementary school to high school age, is to have players focus on memorizing multiple requirements and keeping track of a number of rules and names simultaneously.