Krang is an character from Teenage Mutant Ninja Turtles. He is an alien warlord that wants to take over Earth, with Shredder's assistance. He does not appear in the original Mirage Comics, but rather the Utroms, which were the creatures that Krang was based off of.
X-49 is a robot designed to do the bidding of Aku, but upon seeing the immoral nature of his actions, he retired. Years later, Samurai Jack returned to the attention of Aku, who kidnaps Lulu, a stray dog X-49 adopted, and forces him to kill Jack.
