Bosses Galore level:
Achieve 100 Mutations.

Shangri-La level:
Achieve 150 Mutations.

Greater detailed head:
Achieve 100 Mutations before the original Bird Lap. When you play the laps again, your head will have greater detail

Hint: Defeating District Attorney:
District Attorney and his goons are very cheap. They will run around in circles and attack when you get close. At the beginning of the level you will have a chance to breed. When you breed, be a Graydon. Next, run near them and they will come close and bark. Attack the one who barks at you. Repeat this until you get near the oasis. Then, lure them into the ditch across from the breeding grounds. They will run around trying to escape. Keep attacking them and they will not lock on to you. Repeat until District Attorney is defeated.