Merlin was a powerful warlock and had no children. He was the cousin to Marvin and also to Aggie Cromwell and the Piper family. He created Merlin's Talisman and Merlin's code. Merlin was also real secret of his creations. Never letting anyone know beforehand, other than Marvin. Usually, he never was around when he was alive when Aggie Cromwell was around 1-2 years old.
Halloweentown (film)[]
Merlin didn't have a role, but he was mentioned when Marnie and her siblings try to power up Merlin's Talisman and Code of Merlin.
Halloweentown II: Kalabar's Revenge[]
Merlin didn't have a role, but he was mentioned when talked about Code of Merlin