Andrew.

John 6:8
One of His disciples, Andrew, Simon Peter's brother, said to Him,

Matthew 4:18
As Jesus was walking beside the Sea of Galilee, He saw two brothers, Simon called Peter and his brother Andrew. They were casting a net into the sea, for they were fishermen.

Matthew 10:2
These are the names of the twelve apostles: first Simon, called Peter, and his brother Andrew; James son of Zebedee, and his brother John;

Acts 1:13
When they arrived, they went to the upper room where they were staying: Peter and John, James and Andrew, Philip and Thomas, Bartholomew and Matthew, James son of Alphaeus, Simon the Zealot, and Judas son of James.