A small, green, glowing rat from the video game ultrakill. It is the hardest boss in all of ultrakill.
Guy: Oh look, its the cancerous rodent
cancerous rodent: nuh uh
Guy: *Instantly dies*
the funny rat from ultrakrill
the cancerous rodent is the hardest boss in ultrakill, hands down, has 1 septillion health or something, extremely hard to hit, all attacks fucking oneshot you
(the rodent can literally be killed by a simple punch)