A deranged homeless woman growled, “That’s my baby!” as she tried to snatch a 3-year-old boy from his stroller in front of his grandmother in Gramercy Park on Tuesday, cops said.

The disturbing incident occurred in front of 253 First Ave. in Manhattan around 9:30 a.m. when suspect Victoria Parkes, 39, walked up to the baby and his grandma and made the claim, bizarrely adding, “They just changed his face,” according to cops.

Parkes hit the grandmother in the face during the struggle and tried to snatch the child, police and witnesses said.

“She was trying to say it was her baby,” said the grandmother, who gave her name as Barbara, to The Post.

A witness who works at Empanada Mama nearby said he saw the homeless woman when he arrived to start his shift around 7 a.m.

He said he saw the two women later fighting and intervened. 

“When I go out, they were fighting over the baby,” said the man, who only gave his first name, Oscar, to The Post. “The [homeless] lady who was here was trying to grab the baby [out of a carriage].” 

He said the grandmother was trying to protect the child.

“They both were yelling and fighting over the baby,” he said. “I tried to help the lady, and then suddenly, a lot of women were around.”

Police were called, and Parkes, who is homeless, was charged with assault, cops said. She was given a desk appearance ticket for a later court date, cops said.