'The Twelve' in the Bible

Jesus said therefore to the twelve, Do ye not also want to go?

Jesus answered them, Did I not choose you the twelve, and one of you is a devil?

But he spoke of Judas Iscariot son of Simon. For this man, being one of the twelve, was going to betray him.

But Thomas, one of the twelve, called Didymus, was not with them when Jesus came.