I may or may not have paid nearly $20 to get this bare metal blob. But honestly this one had the best face detail I'd seen on this model and I decided not to quibble over the extra bucks.
This mini came in a Grenadier box set, specifically 5004 Tomb of Spells, which contained about 20 figures.
The Larva (aka "Soul Larva") as a monster appeared in the 1977 AD&D Monster Manual. It may have appeared before that, but I don't see it in TLB vol 1 or in Holmes Basic. It is inspired by Roman demon mythology. In lore, it is the lowly form of a trapped soul, controlled by hags and used by various evil magicians to create imps and such. Mostly it just has a nice "gross!" vibe to it.
Here are some pics after painting. I wish I had done the faces better, but damn they are small!!!