RT-55J

RT-55J is the sub-boss of Sting Chameleon's stage, a big sumo wrestler robot. It guards the capsule where the Body Part (Arm Part in Mega Man Maverick Hunter X) upgrade can be found. In the remake Mega Man Maverick Hunter X and the Rockman X manga, it talks with a robotic voice. Its body is very resistant, and its weak point is its head. RT-55J attacks by jumping over the player and trying to catch him with its extendable claws, ramming the player in the wall if successful. If the claw hit a wall, sometimes it will pull itself near the wall to hit the player in the way. RT-55J also attack with punches in Mega Man Maverick Hunter X.

Strategy
RT-55J will try to jump on X, and, if in range, he will shoot a claw out at X to try and grab him to slam him into a wall. If X has the buster upgrade, keep charging to full level. If not, don't waste time charging, just shoot him rapidly. A good strategy is, wall-jump up a wall while he's jumping at X, then jump over and in front of him. He will try to jump on you or try to grab you with one of his claws. If he uses his claw, dash out of range and rapidly attack him. It will cause much more damage than a single charged shot. But even better is charge up while wall jumping, and do the aforementioned strategy, and when he sents out his claw, dash out of the way, release the charged shot and hit him with a flurry of small shots.

Trivia

 * RT-55J is similar to Auto, though its head resembles that of a Scrap Robo.
 * In fandom, it's said that RT-55J was created by Dr. Light to protect the capsule, and some say that RT-55J is an upgrade of Auto.
 * Another similarity is in the names, RightoT (Auto's Japanese name) and RT-55J.
 * Two unnamed robots from Mega Man Zero that join the Resistance after the second mission bear some resemblance to RT-55J, although they are smaller and orange in color.