I picked up some Reaper Bones to give me all the duplication options for a D&D "Black Pudding" alongside the Wizkids miniatures I already have. The larger one is marketed as a "Carnivorous Pudding" while the smaller ones are "Acidic Ooze"s.
Here's a size comparison to the Wizkids models. The "Carnivorous Pudding" is smaller than the larger Wizkids model, and while it's a bit bigger than the smaller Wizkids one, they'll do OK on the same table as two that are technically the same size. And the "Acidic Ooze" is just the right size for smaller, broken off ones.