Who is John Proctor's slave in Scene 1 of The Crucible?

Proctor does not have a slave in The Crucible.  He and his wife do, however, have a servant girl--Mary Warren.  This relationship is described in Act 2 of the play.

If you are referring to Tituba, she is actually Rev. Parris's slave.  He brought her to Salem from Barbados which is ironic in and of itself because he is a minister.