Schwabl is Marceline's pet zombie poodle. He appears in "It Came from the Nightosphere" inside Marceline's house. He is behind Finn most of the time and walks into another room when Finn starts beatboxing.
Schwabl is fluffy and white with black eyes and a black nose. With a tuft of fur on his tail. He looks like a normal poodle.
- Pendleton Ward has confirmed that Schwabl is based on his friend Marie's dog who has the same name. Schwabl is a white male poodle that has recently passed away and is seen on the show as Marceline's zombie dog that roams around her house.
- In his concept designs he has guts and skeleton visible.
- In "Marceline's Closet," Jake uses a dog door to enter into Marceline's house. It can be assumed this was built for Schwabl.
- Schwabl is named after Marceline's favorite deli in a sunken mall that Simon took her to when she was young (As mentioned in Adventure Time: The Enchiridion & Marcy's Super Secret Scrapbook)
- Schwabl was found in that same mall by an older Marceline
- When Marceline was first turned into a vampire, she drained Schwabl of his red color, that he initially had, and nearly killed him; however, Marceline found and stole the Enchiridion from a group of wizards, and used an incantation to save his life, turning him half-ghost in the process
- This seems to be contradicted in "Everything Stays" which reveals that Schwabl was white before Marceline became a vampire. However it is possible that he was turned red by some unknown means some time after Marceline's transformation.
- Simon mentioned that he will leave Marceline a friend before he leaves her in "Everything Stays" who won't leave. It could be a clue as to how Schwabl ended up with Marceline.