A large (fat or manly) female that mingles with a group of incredibly attractive women in night clubs. The battle pig will scare away men attempting to interact with the attractive females. The only way to bypass the battle-pig is for a self-sacrificing man to offer himself to the battle pig so that his friends may get close to the attractive females.
To take something small, that doesn't quite qualify as a theft. Probably from the Danish "skæv" or the Dutch "scheef", both of which are pronounced similarly, meaning "askew, or not quite right'. To change an item's ownership without permission, but only something small and of little worth.
"I skeefed an apple off the neighbor's tree." "I skeefed some chips outta your bag when you looked away." "Don't skeef my chair when I go to the bathroom."