Splatter Phoenix is a minor villain in Darkwing Duck, and notably the only recurring villain on the series to be killed off.
A rejected artist known for her pompous speech (in "Paint Misbehavin'," she proclaims herself a "daringly innovative pseudo anti-neo post-modern deconstructionist"!), her chief weapon is a brush covered with paint that can allow her to enter paintings, animate them, or even to paint wholly new (and usually surreal-looking) creatures that help her.
Her second (and seemingly final) appearance was in the episode "Paint Misbehavin'," where it was revealed that she, like her creations, is actually painted, possibly by herself. In this episode, she was melted when splashed with turpentine. It is implied by Launchpad that she is actually aware that she herself, along with the entire universe of the TV series, is actually animated/painted by "some higher being."
Splatter Phoenix's popularity with the viewers eventually led to her being brought back in Joe Books' Darkwing Duck comic book. In issue #6's story, an in-universe comic book artist (who resembles the comic's artist, James Silvani) is asked by a fan to draw Splatter Phoenix, which he does use a new supply of ink provided to him by a mysterious benefactor. When he does, though, Splatter Pheonix rises from the drawing, and upon seeing that she's at a comic book convention, begins wreaking havoc. Darkwing and Honker spot her and chase her into several comic books (fittingly, with the art style changing with each one), along the way finding out that she is bound by the logic of the comic worlds they go into. They eventually manage to put her in an ad for Mostess™ Veggie Pies (a parody of Hostess Fruit Pies), and then closing the comic while she's distracted eating the snacks.
Spoilers end here.
Phoenix is one of the few characters in the series to die onscreen, the other being Major Synapse.
Phoenix's death in the show is closely similar to the Wicked Witch of the West's in the 1939 film, The Wizard of Oz (The Witch is melted by water; Phoenix is melted by turpentine).