A reflexive pronoun stands in place of a noun and indicates that the subject itself is affected by the verbal action.
ὃς ἔδωκεν ἑαυτὸν ὑπὲρ ἡμῶν (Tit 2:14)
who gave himself for us
It is found in the NT in the following forms:
ἑαυτόν (αὑτόν) himself
ἑαυτήν (αὑτήν) herself
ἑαυτό (αὑτό) itself
ἑαυτού ourselves, yourselves, themselves