'The Twelve' in the Bible

Jesus therefore appealed to the Twelve. "Will you go also?" He asked.

"Did not I choose you--the Twelve?" said Jesus, "and even of you one is a devil."

He alluded to Judas, the son of Simon the Iscariot. For he it was who, though one of the Twelve, was afterwards to betray Him.

Then said Judas (the Iscariot, one of the Twelve--the one who afterwards betrayed Jesus)

Thomas, one of the twelve--surnamed 'the Twin' --was not among them when Jesus came.