>>96067747
You could be different animals of filthy like rats, cockroaches, giant flies, but I think the best option is a literal shit elemental. Druids have a history of being able to transform into elementals. So if you want to be a bear, you're a shit elemental (excremental) made of shit, or if you want to be a wolf a wolf made of shit. Or see if your DM will just let you be an excremental on its own. https://www.dandwiki.com/wiki/Excremental_(5e_Creature)