Board Thread:Manga Discussion/@comment-33060348-20170913222854/@comment-17259909-20170917031942

Gon and Killua are still kids, mind you. They haven't even gone through puberty. I doubt they'd have the wisdom to be a Zodiac; it's more than just strength and skill.

Now, in about 6 years time, they could be Zodiacs, and they would need to identify with one of the animals. I'm thinking the rabbit for Gon and the snake for Killua.