Episode 02
Page 02
I just noticed that Gaur is missing two more pairs of horns in the last panel. Anyway, as you can see, Gaur rips out a fistful of hair to stuff Kedamono's wound. When digested, the fruit of the World Tree causes the cells of the body to mutate. Gaur's hair, having contact with Keda's bloodstream and organs, became a factor in the mutation, explaining his new hair color and horns. When I was going through the last episode, I had been trying to figure out a way to explain Kedamono's appearance as a superbeast, since his design was just imported from the last PoL, and this seems to do the job nicely.