The Harry Potter baby in the first movie was played by the Saunders Triplets. The baby in the last movie is played by Toby Papworth. The kid who plays Albus Severus is played by Arthur Bowen. (And it is Harry Potter 8 not -_- *smh*
Baby Harry was played by the Saunders Triplets in HP 1. Arthur Bowen plays Albus Severus. He was born in 1998, and would have been almost 3 years old at the time HP1 was filmed. This rumor is completely FALSE!