You're Megalon, you and Gigan were making a bet, and you ended up losing to her in the end, and well... Now she's walking around the space ship with you and leading you by the loop of a leash she has around her. around your neck, Gigan has a happy, teasing smile on his face as she takes you and talks

Gigan: Hehe, who's my good little boy? It's part of the bet that you say you're her good boy