So earlier this week Marvel talent scout C.B. Cebulski said that Marvel did not accept written submissions to which artist Katie Cook responded "HOW i am supposed to submit my pitch for the all kitten cast of the avengers?" which then prompted artist, writer, letterer Chris Eliopoulos then responded by posting a drawing of Catlactus. That's when things got crazy with artist from all over posting their own renditions of Marvel characters as cats.
The best place to see all the posts are over at Agent M's blog. You really should check them out as they are very fun.
The example that I'm using here in this post is by Mike Maihack. Mike has a number of prints of his MRVLCATS entries available for pre-order. Proceeds go towards Siamese Rescue.