Fuligo

Fuligo is a widespread genus of plasmodial slime mold.

It's aethalia are the biggest myxomycete fructifications, and among the most commonly seen.

In Finland one unusually prominent species with a bright yellow plasmodium, Fuligo septica, was believed to be used by witches to spoil their neighbor's milk. This gives it the name paranvoi, meaning butter of the familiar spirit.