Pet Avengers
I don't imagine this'll be a hard sell. Back in 2009 a mini-series united a number of Marvel Universe animal sidekick characters as the Pet Avengers. Among their number were Falcon's pet bird Redwing, the dragon Lockheed (whom I remember as Kitty Pryde's companion during her Excalibur days), the 1980s comedy creation Throg (the Frog of Thunder), and, of course, prominent member of the Inhumans Lockjaw - an over-sized dog from the moon. That this exists in the comics is all well and good - only intended as a bit of fun. The beauty of fantasy comic books like this is that you can do anything and if the Pet Avengers made even one child smile, then who am I to douse those cornflakes with urine? But in the cinematic universe? This could never reasonably be expected to happen. And I'm sure I don't even have to expend any energy explaining why. The moment a huge CGI hound is casually strolling the Avengers tower you'll know things have gone too far and it's time for a reboot. That said, it's not beyond the realms of possibility that Marvel owners Disney might someday seek to make an animated film version of these characters. In fact this is probably the Marvel property best suited to traditional Mouse House talking animal fare.