Gamerizer

Gameriser (ガメライザー) is the boss of the second Wily Stage. He spits flames that can damage and stun Mega Man (like Turbo Man's Scorch Wheel), charge at Mega Man while in his shell, and lift off to send mini-turtles at him.

For the large turtle, hit his head with a charged Wild Coil. For the little turtles, the best bet is with Slash Claw.

With good timing you can also use Danger Wrap on the little turtles to wrap them into bubbles and then push them into the large turtle's head for alot of damage.

Trivia

 * The name Gameriser is a play of Gamera, a giant turtle monster.
 * This boss is similar in appearance and abilities to Thunderbird 2 from Gerry Anderson's "Thunderbirds".