You honestly think that WW Hulk could beat a Sun-Eater?
And tapping into the current set of animals across the Universe isn't Buddy's only power.
As the World War Three/Mageddon arc shows, Buddy is also capable of taking on the power of animals from the future . A millions of years evolved Sun-Eater couldn't beat the Hulk?
Animal Man stomps.
He can tap into the strength of creatures that hunt in event horizons etc. (There goes Hulk's physical advantage of the bat).
He can tap into the energy abilities of a Sun Eater or any number of animals that have appeared in the comic Universe.
How can anyone say WWH wins with a straight face.
If Animal Man has the right mind for it, he can unleash the strength of an animal that over powers black holes etc.
If Animal Man uses his powers properly, I wouldn't even consider this fight fair.
Yeah- animals that can withstand the pressures of event horizons, the Bleed, warp-hole travel.
Faster than light speed, FAR more than planet destroying strength, electrical voltage in far excess of anything I've ever seen anyone lower than high herald manipulate.
Hell, he could even just give himself the attributes of a regular human from ten billion years in the future, like that one guy that stomped all over the freaking Legion of Super Heroes.
Sun-Eaters, Rannian sand-beasts, sentient Suns....
And Buddy can take more attributes than one animal at a time. If he drops in with the relative mass, durability, and strength of a Sun-Eater moving at faster than light speeds, using energy bolts from the Red, he'd smash the earth into pieces and not even notice the impact. He could take hits from the Hulk and they literally wouldn't even register.
Buddy Baker is a beast (my apologies). The only reason he's not the most powerful superhero in the multiverse is that he's too relaxed of a guy, and prefers being with his family and hanging out at PETA rallies.