The first reference to Regina Phalange is during season 5, when she pretends to be "Doctor Phalange", Ross' brain doctor, claiming that names are interchangeable in his mind.
The first reference to Regina Phalange is during season 5 following Ross saying "Rachel" instead of "Emily" at his wedding. She pretends to be "Doctor Phalange", Ross' brain doctor, claiming that names are interchangeable in his mind.