Piggyback. Or would that be "bear-back" ?

"A polar bear cub hitches a piggy-back ride on its mother as they swim through the Arctic Ocean in Svalbard, Norway"  Picture: Kevin Schafer / Barcroft USA

A Picture of the Day from the Telegraph back in 2012.

Now I'm wondering about the etymology of "piggyback."  Did it have anything to do with pigs?  No time to look it up now.  Perhaps someone knows, or can look it up and report back to the class tomorrow.

Indirectly via a little bit of this, a lttle bit of that, a little more of...