Robbie Benex is a descendant of Majotourbillon and the grandson of Roy Benex. He has the special ability to which allows him to communicate with animals.
He is one of the few human characters in the series to discover the Ojamajo's identities.
The reason why the Ojamajos didn't turn into Witch Frogs was became Robbie is related to a witch.
It was revealed that each individual born in the Benex family would have a special power. For example, Robbie's grandfather had the ability to communicate with plants, and his Great-Grandfather could briefly freeze time.