For anyone who is familiar with Obelix but has no idea who Idefix is, it's the original French name for Obelix' dog, Dogmatix. Idefix is a pun on the French expression idée fixe (fixed idea) meaning an obsession.
"It's like Idefix thinking he's leading Obelix around on a leash."
I don't think I have seen Idefix being on a leash ever .. he just runs around free. And there are indeed many dogs on a leash, who lead their "masters" who just follow behind.
I picked them for their difference in relative size and strength, not to suggest that Idefix would ever accept a leash or because there are other dogs that lead their masters around.
