From The Mega Man Universe
Big Eye is a surveillance robot, made to stand guard and watch for intruders. When it spots intruders it will try to stomp on them. Big Eye is very large as far as most robots go and has very durable armor.
Big Eyes were among many robots reprogrammed into minions of Dr. Wily in his first world domination plot, and were mainly used as "guards" for the Robot Masters, with one each stationed at the end of Cut Man, Guts Man, Ice Man and Elec Man's areas. Three Big Eyes were also used as the first line of defense for Dr. Wily's Robot Manufacturing Plant.
Big Eyes will continuously jump towards Mega Man without resting. They have two heights to which they will jump to - a short jump which covers slightly more horizontal distance, and a high jump that covers less horizontal distance. This high jump is the only one Mega Man is able to run beneath, which is his only hope of getting past the large robots unscathed if he cannot destroy them in time, as collision with them (their only attack) damages him critically. If he jumps just before a Big Eye lands, it will sometimes (but not always) trigger its high jump in response.
Because Big Eyes are often hard to defeat, owing to their high endurance, a better strategy is to try to avoid it. The Ice Slasher helps the most with this, since it will let Mega Man freeze them in midair during their high jump (or he can freeze it on the ground, allowing Mega Man to destroy it before it thaws). If he chooses to fight them, three Guts Blocks thrown with the Super Arm are enough to kill them (alas, this strategy can only be put to use in Cut Man's sector and the first area of Wily's lair), though the Thunder Beam is a decent alternative. Mega Man
Mega Man: Dr. Wily's Revenge
Big Eyes were once again utilised when four of Dr. Light's Robot Masters were reprogrammed for evil by Dr. Wily. They were stationed in Cut Man, Ice Man and Elec Man's sectors, as well as both Wily Castle and Wily Station.
Big Eyes have a lot less endurance than their prior appearance (going down in eight Mega Buster shots as opposed to twenty) and now take long, three second rests between jumps (which again come in short and high varieties). However, they can only be damaged while they are jumping. Once again, the Ice Slasher is one of Mega Man's best ways to get past a Big Eye as he can freeze it and either run under its high jump, or damage it while it hangs in the air. The Rolling Cutter, Thunder Beam and Bubble Lead can destroy a Big Eye in very little time. Mega Man: Dr. Wily's Revenge
Captain N: The Game Master
Within Cuts Man's world, Big Eye was the largest enemy there. The N Team struggled against Big Eye upon coming to it, before ultimately getting squished by the titanic robot. This merely sent them back to the start of the world, though, and when they returned to Big Eye, Kevin managed to defeat it by luring it off a cliff. Mega Trouble for Mega Land
Mega Man (Archie Comics)
As Mega Man began to attack Dr. Wily's fortress, a squad of Big Eyes moved to attack him outside. Mega Man destroyed some of them as he used the Super Arm to tear his way inside. Trouble Get!