Gumbus
Option 1 is best but his human identity is that of a zooologist professor And for love interest they could be either 1. Beatriz Bonilla da Costa / Fire Or 2. Ice Ice / Tora Olafsdotter And for a villain with romantic attraction, think the cat woman to his Batman, it could be maybe Quee Bee or Poison Ivy due to their shared love of nature
ummm bruv I'm gonna tell ya something real quick. the character you have created is a hunter. that means he goes for the hunt but since you said he's a animal behavior scientist he'll go for the hunt plus research it also means he'll have to kill a few people. so he won't fit with the justice league because of all the restrictions. so I would go with helper. he helps them and every other team on occasion like a mercenary.