Pact of the Chain

You learn the Find Familiar spell and can cast it as a Magic action without expending a spell slot.

When you cast the spell, you choose one of the normal forms for your familiar or one of the following special forms: Imp, Pseudodragon, Quasit, Skeleton, Slaad Tadpole, Sphinx Of Wonder, Sprite, or Venomous Snake (see appendix B for the familiar's stat block).

Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to make one attack of its own with its Reaction.