The term "princess bubblegum r34" often refers to a specific type of fan fiction and fan art centered around the character of Bubblegum Princess from the animated series Adventure Time. This content is typically rated as mature or adult-themed, often featuring explicit sexual content and themes that are not suitable for younger audiences. The "r34" in the term is a reference to the 34th entry in the Japanese rating system for adult content, indicating that the material is intended for mature viewers.

These works explore the character's personality, relationships, and physical attributes in a more mature and often sexually suggestive manner. While the original series Adventure Time is known for its whimsical and family-friendly content, fan-created material like this can take on a life of its own, catering to a different audience segment.

It's important to note that such content is created and consumed by fans and is not officially sanctioned by the show's creators. The exploration of these themes can be seen as a way for fans to express their creativity and affection for the characters, but it also raises questions about the boundaries of fan-generated content and its potential impact on the original franchise's image.