Blood Fountain

When this artifact enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{3}{B}, {T}, Sacrifice this artifact: Return up to two target creature cards from your graveyard to your hand.

Foundations Jumpstart

When Blood Fountain enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{3}{B}, {T}, Sacrifice Blood Fountain: Return up to two target creature cards from your graveyard to your hand.

The List

Innistrad: Double Feature

Innistrad: Crimson Vow

If an effect refers to a Blood token, it means any artifact token with the subtype Blood, even if it has gained other subtypes.

Some triggered abilities trigger "whenever you sacrifice a Blood token." These abilities trigger regardless of why you sacrificed that Blood token.

You can't sacrifice a Blood token to pay multiple costs.

Blood

{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.