What is "Rudolph the Red-Nosed Reindeer" son's name?

"Rudolph the Red-Nosed Reindeer" is a popular Christmas icon and legend who is well known for his glowing red nose which he used to guide Santa Claus's sleigh on a foggy Christmas Eve. He is also Robbie's father and an unseen character in "Hooves Of Fire" (1999). However, even though Rudolph is never directly mentioned by name in "Hooves Of Fire, references about him are replaced by the first and second films' antagonist Blitzen interrupting with the phrase "Don't say that name!" or something similar and gagging anyone who tries to say it.

Two other BBC animations, "The Legend of the Lost Tribe" (2002), and "Close Encounters of the Herd Kind" (2007), also, carry on the legend by introducing Rudolph's son, Robbie the Reindeer.

As for Leroy, Rusty, and Ralph, Leroy the Redneck Reindeer is Rudolph's cousin, Rusty Reindeer is Rudolph's younger brother, and Ralph, the Infra-Red Nosed Reindeer is Rudolph's older brother.