Ash

Ash is Marceline's immortal ex-boyfriend who appears in "Memory of a Memory." Marceline broke up with him because he sold Hambo, her favorite teddy bear, to Maja in exchange for a new Cherry Blossom Wand. Disguised as a Rag Wizard, he used Finn and Jake to get a hold of Marceline's memory core containing her memory of breaking up with him so that he could destroy it, effectively making it like the break up never happened for her. As Marceline wakes up, he and Marceline go to his house where he asks Marceline to make him dinner. She then finds out what happened by viewing Finn's memory of her memory of breaking up with him. Marceline comes out of Ash's house with Finn and they jump on him and kick him, while Jake stretches into a giant sized foot and stomps on him at the end.

Rag Wizard
The Rag Wizard is an alias Ash created to trick Finn and Jake. This disguise makes him green skinned with a beard that has its end tied, and clothes made of rags making him look more like a hobo than a wizard. He allegedly had no arms, and thus used his feet to interact with things. He claimed that he was Marceline's "spirit animal." As soon as Finn and Jake find the memory of Ash and Marceline's break up, he reveals that he is really Ash.

Appearance
Like Marceline, Ash has pointy ears and bluish-gray skin, even though he is not a vampire. His skin is only slightly darker than hers. He has three white mohawk-like wisps of hair, similar to the hair style Marceline had in the episode "Go With Me." He always carries a pouch of Magic powder on his belt, both as himself and in disguise as the Rag Wizard. When he is being beaten up at the end of the episode, his eyes are briefly white.

Personality
Although Ash appears to be a nice guy in Marceline's first memory of moving into the Tree Fort, he soon reveals himself to be inconsiderate, cruel and sexist. Ash also sold Marceline's childhood toy Hambo to Maja, thinking that it was very important to her (in fact, because it was important to her). After stealing Marceline's memory, he demands that she gets back in the kitchen and make him a turkey sandwich with tomato and pickles. Ash is arrogant and appears to dislike "mere mortals," as he told Marceline he doesn't want her to spend time with Finn and Jake (though, he may have just told her this to keep her from finding out the truth behind their breakup). He is very vain and selfish.

Trivia

 * Ash is still alive, according to Adam Muto.
 * Ash's full body suit is similar to the Earl of Lemongrab's.
 * Ash can fly by waving his wand and uttering the phrase "Ashicus Flyicus." This allows him to levitate and seemingly phase through solid objects, as seen when he passes through the roof of Marceline's house.
 * Ash and the Witch both are shown to use spells that are essentially words with the suffix -icus added on.
 * Ash bears a resemblance to a Regular Show minor character named "Techmo."
 * In the comic book series, he is in Lemongrab's band "Unacceptable."
 * He can fly, levitate, and pass through solid objects.
 * It is confirmed by Cartoon Network UK that Ash is immortal.
 * In "The Adventure Time Encyclopædia," a newspaper clipping is shown that reports that he was arrested for "Fencing Stolen Property, Impersonating a Wizard, Stealing Memories, and Being a General Pain in the Butt."

Quotes
"Oh, I sold that teddy bear that you love so much...to a witch."

"Don't you guys get it? I out-brained you! That wasn't a memory of a sleep spell you brought me. That memory was our break up!"

"What's all this hullabaloo?"

"Yo, Mar-Mar. What's with the chump? C'mon, I said no chumps."

"Ash gets hungies at 8:00. You need to get back in the kitchen and make me din-ner. I want a turkey sandwich with to-ma-to. Also pickles."

"Ohh...I can't see...Somebody call my mom..."