|Species||Winged cat-like creature|
Lava Dragon (formerly)
Mutant sea creature (formerly)
|Voiced by||Dee Bradley Baker|
Molto Larvo is a creature that attacked the Glass Kingdom a long time ago. Marceline and Princess Bubblegum fought against him, saving the Glass People from ruin. He served as the main antagonist of "Obsidian".
Larvo is a large Yunnan lake newt-like creature with yellow eyes and small, sharp teeth.
Larvo's younger self was a mutant tadpole-like sea creature who was the sole survivor out of all of his siblings when a sea predator attacked them, Larvo barely escaped the monster's sharp teeth and gained a scar on his forehead which he hides using a rock shaped like a mask. Larvo crawled through a small crack under the sea and laid dormant inside a cave in the Glass Kingdom for years within the lava flows.
Hundreds of years ago
Larvo started to evolve and grew larger. He became hostile towards the Glass Kingdom for unknown reasons. In order to stop him, the Glass People summoned Princess Bubblegum for help. Marceline, Bubblegum's girlfriend at the time, came as well. Bubblegum managed to contain Larvo with a force field, but the generators were knocked down by an angry Marceline. However, the Vampire Queen's song, "Woke Up", managed to drive Larvo back into the Furnace, where the Glass People kept him locked up. In order to prevent another possible escape, the Glass People sang Marceline's song annually to keep him locked up (however, they misheard the lyrics and sang it totally different). Larvo then spent centuries growing bigger and stronger, never forgetting his imprisonment at the hands of Marceline.
Hundreds of years after his original defeat, Larvo is accidentally awakened by Glassboy, a Glass Person seeking to use the Furnace to heal his cracked face. While the nobility attempted to contain him, Larvo spawned three Glass Creatures to find and kill Marceline. However, she defeated them upon returning to the Kingdom with Bubblegum and Glassboy. Marceline played "Woke Up" to drive Larvo back again, but he had become too strong for it to have an effect. While Marceline left to figure out a new song, Bubblegum found a way to crystallize Larvo using the root beer of her Elemental powers. Larvo was released and sprayed with copious amounts of root beer, but it only gave him crystalline spikes all over his body.
- Larvo appears in the center of the "Obsidian" promotional poster, right above Marceline.