noun, plural bip·pies. Slang.
Origin of bippy
by 1968, "buttocks, ass," U.S. slang, the kind of thing that once sounded naughty on "Laugh-In" (and briefly popularized by that program). As it often was used with you bet your ... it may be nonsense chosen for alliteration, but there may be some whiff of bipedal in it.