Titan:

> According to Cassini data, scientists announced on February 13, 2008, that Titan hosts within its polar lakes "hundreds of times more natural gas and other liquid hydrocarbons than all the known oil and natural gas reserves on Earth." The desert sand dunes along the equator, while devoid of open liquid, nonetheless hold more organics than all of Earth's coal reserves.

https://en.wikipedia.org/wiki/Lakes_and_rivers_of_Titan

The next obvious question is where do they come from since presumably there weren't dinosaurs and plants dying there 300 million years ago.

Went on a bit of a rabbit hole and it appears that there is a lot of methane in the atmosphere and that gets broken down via photolysis into hydrocarbons somehow, and the methane likely is there from the formation of the moon originally via methane ice.

https://en.wikipedia.org/wiki/Abiogenic_petroleum_origin

Does Titan have enough oxygen to allow the combustion of hydrocarbons?