I believe this is the debut EP from Germany's Toxic Mutants. Fittingly, their sound is dirty and growling. It gets especially sludgy on "Formicula" and "Attack of the Killer Funghi", both of which culminate in a satisfying meltdown. Even their most upbeat tune has a dirty rumble to it. This all comes across very well thanks to time well spent in the studio, so that sludge is nice and crisp just how I like it.
Free download on bandcamp!