Your mum in the ultimate come back for anything that anyone says. It originated back in the 2000's when teenagers found that answering questions was just plain boring, so instead, 'You Mum/Mom' became the lazy excuse for everything.
"Excuse me but what are you doing?"
"What are you having for breakfast?"
When somebody is frog-legged, it means that they have very lanky and/or wobbly legs. Most of the time 'frog-legged' human beings or animals can jump very high, but are quite unfortunate in the bedroom, as their lanky legs get in the way of everything.
"Hey look Jessica Simpson is really frog-legged".
"Yeah I know right, her legs are so lanky!"