(Cover) - EN Showbiz - Chaz Bono has revealed his father used to call him Fred.

Chaz, the child of musical icon Cher and her former husband the late Sonny Bono, was born female but recently had gender reassignment surgery to become a man. He began the process in 2009, and legally changed his gender and his name from Chastity to Chaz.

"He called me Fred," Chaz said on The Tonight Show with Jay Leno.

Sonny's male nickname for Chaz stemmed from a weekend visit the pair took to a Palm Springs toy store that Chaz loved to go to. The shop had key chains and other gifts with names on them.

"They never had my name, so my dad said, Pick a name - what do you think of Fred?'" Chaz explained. "And I apparently really liked it. It stuck for quite some time."

Cher has publicly supported her son's choices but Chaz admitted that his mother did have fears for him and worried people would mock him.

"She was really scared for me and I think she said to me, They're going to make fun of you on late night talk shows,'" Chaz revealed.

Chaz was concerned about how his decision to change from female to male would affect his mother.

"My mum is a public figure, so what am I going to be putting her through, and is she going to be crucified for it?" he said.

Chaz has written a book called Transition about his experience and has been featured in a television documentary called Becoming Chaz. (C) Cover Media