Rufus is a cat. Owned by Molly's grandmother.
Rufus was created by Rainbow Rowell and Kris Anka and first appeared in Runaways Vol.5 issue 4 (2018).
Major Story Arcs
Molly and Rufus
After Molly stayed with her grandmother for some time, she mett many of her cats, including Rufus. Moly was taken from her grandma by her old teammates, the Runaways. Grandma would not allow it, but eventually the Runaways succeeded. Molly took the cat Rufus with her on their journey.