Where do Vampiric Scraps drop?

[Late]

I've gotten those drops but haven't seen any recipes

[Shellkaz]

I haven't seen a single recipe drop. To anyone, from any boss, for any type of equip. I checked in cs and there were none for sale either. This is for Mt. Dang gear.

However to keep on topic, I have seen and gotten scraps drop from all bosses. All types of scraps, including wood and silver.