For Adipose Offspring's last ability, use the toughness of the sacrificed creature as it existed when it was last on the battlefield, which may be different from its toughness in the graveyard.
Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When this creature enters, create a 2/2 white Alien creature token. If this creature's emerge cost was paid, instead create X of those tokens, where X is the sacrificed creature's toughness.
(You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)