The Egg Spiker is the fifth boss encountered in Sonic the Hedgehog. It is fought at the end of Star Light Zone.
For this boss fight, Dr. Eggman flies back and forth across the screen, over three see-saws. Just out of reach of Sonic's Spin Jump attack, he periodically drops spiked bombs onto the see-saws in a basic sequence. These bombs have a short fuse, but before detonating they can be flung back up to hit Eggman's ship as he flies over, if timed correctly, by having Sonic jump on the opposite end of the see-saw.
Alternatively, the bombs can be used as a counter-weight to propel Sonic skyward, by waiting on one side of the see-saw for Eggman to drop a bomb on the other side. This can be difficult if the player does this recklessly, and if positioned incorrectly they may be struck by a bomb from above, thus necessitating care and quick reflexes while battling this boss. It is also possible to hit this boss by just jumping normally, by jumping from the center of a see-saw as Eggman flies over it, but it is very hard, as it requires precision timing.
After eight hits using either method, Eggman is defeated, and Sonic moves on to Scrap Brain Zone.