That would be a 'trebuchet'
This evening I attended a birthday party for my cousin Amethyst's daughter Pie, who just turned six. I was trying to convince Pie that my present would be the best, since I got her broccoli and a miniature cow. (Ok, not really, but it was fun to pretend.)
other cousin Sunny: I think Amethyst's present will be the best. She got Pie a bike.
VBG: Yeah, that will be pretty hard to beat.
cousin-in-law Dave: I got her a flamethrower.
VBG: That would pretty much trump all presents, ever.
Amethyst: Unless you got one of those things...what are those things? You know, that they use to throw cows?