This boss very simple. But you can stuck if you don't understand what to do.
1. Use anvil & wait until snake bash his head upon it.
2. Jump on electricity line with trampoline. Wait for cobra's attack.
3. Use *hole* on place, where he will fall. Look on shadow.
Win.

Quickly use *bubble* before boss attack. After it, on the level you can see three black bombs. Your goal: catch boss on them.

The hardest boss in the game. This bird is real pain. Pattern simple. Use cannon to shoot back balls, that Crow throws in you. After it trampoline to jump above him. Transform blob in anvil and drop it on laying crow. Repeat three times. But sometimes this boss little random & you can't predict what he do next time. So you need little peace of luck.

He need only one hit. But this hit not simple. You need transport stone block from the left side of the screen to the right. Use *trampoline*, *lever* and *doppelganger*. It's easy. But watch for shadows and avoid enemy bullets (?). If you beat Crow & 8 citadel levels (they tough), you can do this too.

Elementary. Use jumpball to avoid his shots. Try to stay on the highest platform. Because he use some acid water that flood all screen except this platform right after he stop shooting. Choose shield. Block two green shots. After go in Mecha & beat him. Repeat three times. Simple.