Eyerok is a stone creature comprised only of two hands, with each containing a single eye (the boss's weak spot). Because of its stone-like appearance, Eyerok might be based on a golem (a creature that was said to have been brought back too life through magic and enchanted earth).
In Super Mario 64, Eyerok is the boss of Shifting Sand Land. He resides in the pyramid but Mario must find a secret entrance to reach his room. It will open when he's been on the top of all four of the pillars on the level. He is fought on a platform that's surrounded by pits on three sides. He can attack by slamming down his fists on Mario which takes 3 HP. The Eyerock can also try to push Mario down from the platform, causing an instant death. The Eyerok can only be attacked when his eyes are open which is only when one of the hands aren't attacking. After both of his eyes have been punched three times, the Eyerok will be defeated and Mario will earn another Power Star.
He is fought on star four in the mission Standing on the Four Pillars in Shifting Sand Land and is fought in exactly the same way in Super Mario 64 DS.
The Eyerok appeared again in Mario Kart DS as the second boss in mission mode. He must be fought by Mario in this version and he can be defeated by shooting green shells at him when his eyes are open. He isn't completely defenseless as he whirls around in the air and comes down, crushing Mario and making him lose a balloon. He also goes ballistic after you hit his eyes two times. He repeatedly comes down hard. So if you wanna be in his way when he goes crazy, thinking your brave, go right ahead. You will get flattened. No doubt about it.
Eyerok can also be split into two words Eye and rock, which is how Nintendo created the name. Also there is the pun "I rock" in his name.
Eyerok has the most health in Super Mario 64 as both his hands have 3 HP each, giving him 6 HP in total. Not even Bowser's final form has that much health.