Let's Make Robots!

Replacing a motor(?) for my Dagu Adventure bot

So I got the Dagu Adventure Bot for my kids for Christmas (and was posting about getting it running around Oct/November).  Well they do love it but it wasn't long before he broke.  I apologize for the overly simplified terms I'm about to use but I'd rather use them then the wrong words.  But it's the left wheel that's the problem.  The black box (presumably housing the motor) that the left wheel is attached to, is screwed into posts in two places using a really tiny plastic piece coming out of the black box.  That piece has snapped (I think they let him fall off the table but nobody is fessing up).

He still appear functional - the wheel still wants to turn, it's just that wheel and motor are no longer attached to the base.

Is this a replacement part, and if so, what am I searching for?  Is it a new motor that I need, and the casing comes along with it?  Or is the motor still fine on the inside, and it's a different piece I should be hunting down to replace the housing?