Again another easy one but somebody is gonna ask long after the rest of us forgot.
Dt the three ice.
Release magmaw target tc, then heart
If he fails to notice a minion hacking away at his health bar, or you wasted your mana screwing around and can't heal him with dragon breath, return to the two hatcheries and alternatly target them and switch back and forth without actually damaging them. Hes fast enough to avoid the damge but regains his health in a couple seconds.
Chicken bombs also heal him
No, don't even try to take out the other magmaw it will fail. But screen shot and beer if you do