The gospels of Matthew and Mark each contain a complete list of Jesus’s twelve disciples, or apostles. The two lists have all the same names. One of the disciples is named Thaddaeus, and Judas Iscariot is the only Judas on the list:

• Simon Peter
• Andrew
• James son of Zebedee
• John
• Philip
• Bartholomew
• Thomas
• Matthew
• James son of Alphaeus
• Thaddaeus
• Simon the Zealot
• Judas Iscariot

The gospel of Luke also has a list of the twelve disciples, but this one has two people named Judas, and no one named Thaddaeus:

• Simon Peter
• Andrew
• James
• John
• Philip
• Bartholomew
• Matthew
• Thomas
• James son of Alphaeus
• Simon the Zealot
• Judas son of James
• Judas Iscariot

The book of Acts lists all the same apostles as Luke except Judas Iscariot, since he was dead by that time. The gospel of John doesn’t have a list of all twelve disciples, but it agrees with Luke and Acts that there was a Judas other than Judas Iscariot among them.

But John also says one of the disciples was named Nathanael. He’s not mentioned in any other book.