The man who was the voice of Charlie Brown in several "Peanuts" television shows was charged Wednesday with stalking and threatening his former girlfriend and a plastic surgeon who gave her a breast enhancement that he paid for before the relationship ended.

Peter Robbins pleaded not guilty Wednesday in San Diego Superior Court to two counts of stalking and 10 counts of making criminal threats.

Prosecutors said the 56-year-old voice actor best known for his portrayal of Charlie Brown on the TV special "A Charlie Brown Christmas" repeatedly threatened his former girlfriend, calling her as many as 37 times in a 24-hour period on her cellphone and telling her he would kill her and her son if she did not give back his dog and car.

Prosecutors said he also followed and threatened her La Jolla plastic surgeon, calling her office so many times she moved to a hotel temporarily out of fear for her life and hired an armed guard outside her clinic. Authorities said Robbins was demanding a refund for the surgery, according to the criminal complaint.

On Dec. 31, Robbins allegedly confronted his former girlfriend in a hotel room, beating his dog and telling her he would not stop hurting the animal and would kill her if she did not get a refund for the surgery, Deputy District Attorney Elizabeth McClutchey told the judge in arguing that bail be increased to $550,000. McClutchey said he then grabbed his ex-girlfriend by the neck and shoved her against the door before fleeing.

Prosecutors also told the judge that Robbins had been practicing at a shooting range and recently purchased a gun but had not picked it up yet. San Diego Superior Court Judge David M. Szumowski agreed to up the bail to $550,000.

Robbins was arrested Sunday at the San Ysidro Port of Entry after authorities doing a background check upon his return from Mexico spotted a warrant from the San Diego County Sheriff's Department.

Robbins was best known for his performance as the voice of Charlie Brown on "A Charlie Brown Christmas" and "It's the Great Pumpkin, Charlie Brown."

Defense Attorney Marc S. Kohnen told the judge the bail was set too high for a man with no prior criminal record, who has lived in San Diego County for 30 years and whose work is watched by so many children to this day. He called him a "distraught man" and said "this is not a stalking case" but declined to comment on what led to his arrest.

"Mr. Robbins is an eccentric individual," Kohnen told reporters after the arraignment. "He's not a threat to society."

If convicted, he would face a maximum sentence of up to nine years in prison, prosecutors said.