Fadge Biscuit - A biscuit that looks like it was dropped in a sewer and then

A biscuit that looks like it was dropped in a sewer and then stepped on by a dirty sock.

My teacher gave me a fadge biscuit for homework and I cried.

I tried to eat a fadge biscuit and it was like eating a sock full of dirt.

My brother called my lunch a fadge biscuit and I threw it at him.