A worldwide community photographing and learning about wildlife
Elisolimax flavescens
I am in South Africa, have no idea about the size of Quarter but it was about 40mm long.
It might be an African banana slug due to its location but it looks like Ariolimax californicus, a banana slug from California. Desmond.E.S.O suggested the group of banana slugs from N. America so it might be a pet or it got released.