I made a to-scale Max plush for under 20$. 1/4 yard pink soft flannel, 2 yards white, some poly-fil and a coat hanger (to keep his ears upright)
If you're wondering about the awkward shape of the head (and why he has no grin)- I'm making him as the animated series version. His head is squashed because I'm working on his flight attendant's uniform, and the hat looked weird on him when the head was round.
Also, this:
Sam: Holy time-traveling mariachis in a spaceship disguised as a police call box with a medical practitioner! Max! What are you doing with that furball?
Max: You mean my...
Sam: The one in your HANDS, buckethead.
Max: It's a small fuzzy alien that goes around destroying cities and causing mayhem!
Sam: And that's different from you, how, exactly?
Max: Can we keep him, Sam? Please? I see the destruction of Tokyo looming in his big, maniacal eyes!
Sam: I spoil you rotten, little buddy.