He is voiced by Fred Tatasciore.
Carl is a tall, gray rabbit who has a skeletal body and wears a long, black cloak. He also carries a tall and bent walking stick with a carrot tied to the end of it.
He first appeared in the episode "The Grim Rabbit" as he came to take Bugs Bunny but Bugs leads him to a carwash and puts a dead fish in his rope so a bear would attack him, so Bugs could evade him. In the end of the episode, Carl decides to forget taking Bugs' soul, but not before the bear attacks him again.
He made his second appearance in "Grim on Vacation" when he and his wife, Cheryl, relax in Tahiti. Carl chose Tahiti because he knew Bugs was going to be there. Carl constantly tried to kill Bugs. In the end of the episode, Carl had a free month on the island, with unlimited access to all activities.
He made his third appearance in "Your Bunny or Your Life" when he chased Bugs all over town. Bugs escapes while tricking Carl into buying a lottery ticket. Carl chased Bugs but he loses him and gets tired along the way. Carl got arrested for failing to pay taxes on his lottery check.
In "Just One of Those Days", Carl teamed up with other villains to eliminate Bugs.
In "Quiet the Undertaking", Carl chased Bugs to a space museum and they have been locked in the museum. Carl and Bugs became friends until Carl gets ticked off by Bugs.
Carl does not appear in season 2, so he is either permanently written out or was written out for later use in future seasons or episodes.
It is unknown if he will appear in season 3 or not.