Shark Boomerang

Shark Boomerang is a special weapon that Mega Man obtains by defeating Shark Man in Mega Man 3 for the PC. It fires a three-bladed boomerang, presumably sharpened around the edges, straight forward, after a set distance it returns to the location it was fired from.

It looks very similar to the Gyro Attack and acts like Ring Boomerang, but without returning to Mega Man and going through shields.

The Shark Boomerang does 8 damage to Wave Man (PC), 6 damage to Blade Man (PC) and Torch Man, 3 damage to Oil Man (PC), as well as 4 damage to Wily's Second Form.

Trivia

 * In the games data, there are unused sprites of "weapons unlocked", where Mega Man is holding his new weapon.