A "bootyrang" is a person whom was/is your booty call, and as hard as you have tried to get rid of them (throw them away), they keep on coming back like a boomerang
Yo, you know my booty call Michelle? I told her off so hard last week, it hurt her mother. And guess what she did last night? She called me to get some. What a bootyrang!
When you put on tall rubber boots, grab a sheep and put it's hind legs in the boots with your legs. You then proceed to fuck the sheep. This procedure is used to prevent the sheep from getting away.
"Damn man, I am so horny, I'm about to fuck a sheep!"
"Yeah dude, gimme your tall rainboots, I need them for some sheep booting."