Eatle battled Seebik, Lackno, Liam, Dimension 23's Violet Offenders, Will Harangue, Joseph Chadwick, Sir Morton, the Forever Ninja, the Forever Twins, Tummyhead, Sweet-Eels Sparklefunk, OTTO, and the mainstream Violet Offenders
Upchuck battled Liam, Dimension 23's Voilet Offenders, Attea, Milleous, Lieutenant Rana, Raff, Nyancy Chan, Khyber, Khyber's Panuncian/ Ultimate Panuncian, Albedo/ Ultimate Albedo, Vilgax, Doctor Animo, the Mutant Giraffe, and the Technobugs
Ignoring Eatle's durability, Upchuck is sure to win.
Even with Eatle's durability, it would be interesting to see if he could resist his own laser attack. Upchuck eating Eatle's laser, and spitting it back might hurt him. What's more, Upchuck's size gives him speed to dodge attacks. He may also be able to eat Eatle, like he did to Crabdozer. I think that the fact Upchuck's ability being more focused on eating then Eatle's is, as he is more on attacking, that would make Upchuck the winner.
Eatle, he has a horn and enhanced strength. P.S I love both of them but Eatle I like more
Upchuck, because he has no predators
Upchuck, he can eat everything (except earth food) ironic isn't it still upchuck eats lasers he will just give it back harder, and eatle is vulnerable to lasers.
eatle will eat upchuck and shoot him as a laser. bye, upchuck!
Upchuck is small and squishy.
Eatle is big and strong.
I don't think the eating powers would even come into play here, Eatle would just crush Upchuck.
Though Upchuck did survive a lot of hits in the OS.