hmmm alright here's my compromise; as there are pros/cons for each, neither really wins over the other. therefore, make the unupgraded be a 1/2 with Nibble and Swarm/Ambush (cost 4 or 3), and make the upgraded start as a 1/1 and keep the ability of option 2; perhaps a cost of 5 for the upgraded
i don't really like that Nibble is gravity, but i don't have a better idea