D&D 5E What monsters should inhabit the oil sands?

[Bohandas]

Skeletons with earth elemental traits or vice-versa

 

[Bohandas]

Oh! and also Bilewretches and other servants of Holashner. Holashner's "black bile of the world" seems pretty clearly to be inspired by and based on oil (and bilestone seems to be inspired by coal)

 

[Bupp]

Love this idea. My homebrew World of Eska is based on a far future post magical apocalypse Earth. This will fit in nicely in the Northern Wastes!

 

[MarkB]

I immediately thought of this scene from Mad Max Fury Road:

Some kind of long-legged, broad-footed creature that can stalk through the sands without getting oil all over the rest of itself would work well. Maybe these guys:

 

[Shades of Eternity]

to quote from another forum:
Positive_Curve_8435
"Undead. Crude oil is probably the most death attuned thing in the natural world, considering it's dead things that have sat for thousands of years."

 

[the Jester]

Firenewts, giant striders, tar devils (from 4e's Monster Vault 2), a belker or two hiding away, conflagration oozes, inferno spiders, mephits.

 

[Eltab]

Larry Niven's The Burning City puts a source of magic in/under the LaBrea tar pits. Not quite what you are describing here but you could pilfer his ideas.