This Bible contradiction is from the Skeptic's Annotated Bible.
A servant girl, another girl, and then a crowd of people.
Matthew 26:69-73 View context
Now Peter sat without in the palace: and a damsel came unto him, saying, Thou also wast with Jesus of Galilee.
But he denied before [them] all, saying, I know not what thou sayest.
And when he was gone out into the porch, another [maid] saw him, and said unto them that were there, This [fellow] was also with Jesus of Nazareth.
And again he denied with an oath, I do not know the man.
And after a while came unto [him] they that stood by, and said to Peter, Surely thou also art [one] of them; for thy speech bewrayeth thee.
A servant girl, the same girl again, and then a crowd of people.
Mark 14:66-71 View context
And as Peter was beneath in the palace, there cometh one of the maids of the high priest:
And when she saw Peter warming himself, she looked upon him, and said, And thou also wast with Jesus of Nazareth.
But he denied, saying, I know not, neither understand I what thou sayest. And he went out into the porch; and the cock crew.
And a maid saw him again, and began to say to them that stood by, This is [one] of them.
And he denied it again. And a little after, they that stood by said again to Peter, Surely thou art [one] of them: for thou art a Galilaean, and thy speech agreeth [thereto].
But he began to curse and to swear, [saying], I know not this man of whom ye speak.
A servant girl, a man, and then another man.
Luke 22:54-60 View context
Then took they him, and led [him], and brought him into the high priest's house. And Peter followed afar off.
And when they had kindled a fire in the midst of the hall, and were set down together, Peter sat down among them.
But a certain maid beheld him as he sat by the fire, and earnestly looked upon him, and said, This man was also with him.
And he denied him, saying, Woman, I know him not.
And after a little while another saw him, and said, Thou art also of them. And Peter said, Man, I am not.
And about the space of one hour after another confidently affirmed, saying, Of a truth this [fellow] also was with him: for he is a Galilaean.
And Peter said, Man, I know not what thou sayest. And immediately, while he yet spake, the cock crew.
A girl at the door, several anonymous persons, one of the high priest's servants.
John 18:15-17 View context
And Simon Peter followed Jesus, and [so did] another disciple: that disciple was known unto the high priest, and went in with Jesus into the palace of the high priest.
But Peter stood at the door without. Then went out that other disciple, which was known unto the high priest, and spake unto her that kept the door, and brought in Peter.
Then saith the damsel that kept the door unto Peter, Art not thou also [one] of this man's disciples? He saith, I am not.