I'm a huge fan of the Thrall of Juiblex prestiege class from 3.5, unfortunately, like many 3.5 features, the thrall of juiblex doesn't have a 1-to-1 translation. Usually, this is where homebrew comes in, but few enough DMs even allow UA content. Given approved, official material, is there a way to replicate as much of a thrall of juiblex as possible through a character build?

I was thinking spore druid is a good starting point, but beyond there I'm lost. There don't seem to be many sources of acid damage or ways to turn amorphous, and as far as slime summoning, there doesn't really seem to be anything unless you refluff a water elemental or mud mephit as ooze elementals. Any suggestions?