Concept art showed that some of the hunters would be dark skinned and likely of a different ethnicity.
Concept art for the seal hunter that kills the seal pup had a different design and depicted him as more sadistic. One design shows him looking like a devil with pointed horn-like hair while the other just shows him bald. He looks a bit like Judge Doom from Who Framed Roger Rabbit (1988).
The hunters have glowing white eyes and sharp claws which helps depict them as predatory monsters.
A pitch for the short showed the animals suffering different demises. The rhinoceros would have been chased by poachers on jeeps, the pelican would have one of his wings trapped in the oil spill, the seal pup would be surrounded by seal hunters, and the whale would be speared to death underwater. Another difference is that the rhinoceros does not have a calf.