|Marceline with her original bass guitar|
Fender Precision Bass
Marceline's original bass is a red, four-string Fender 1951 Precision Bass with covers on the pickup and bridge and two knobs, one for volume and one for tone and a slightly larger pickguard. This bass is featured in the opening animation of every episode. Its only appearance in-story is in "Evicted!," in which she plays it and then carries it around with her while frightening Finn and Jake. This bass has not had an in-story appearance in any episode since, as Marceline prefers to play the Ax bass.
- Main article: Ax bass
Butterfly BassHeat Signature," when Finn and Jake visit Marceline to show her the movie "Heat Signature." The bass is a purple with a blue headstock, the body of which is stylistically reminiscent of a butterfly. Due to its unique construction, it may be a neck-through model. It doesn't appear to have any volume or tone controls, although there is a dark circle on each wing. It has two dark spikes flaring off the top of one of the wings. It is not yet seen to be played by Marceline.
Marceline's Banjolele, or Banjo Ukulele, is an instrument Marceline played in "Daddy's Little Monster" a saccompaniment to the song "I'm Not Just Your Little Girl". Marceline has only played the banjolele in this episode, so the instrument may belong to Hunson Abadeer and it stays in the Nightosphere.