A ravenous robber bit a teenage dog-walker in Manhattan in a bizarre robbery, police said Tuesday.

The teen was walking his dog near West 205th Street and 9th Avenue in Inwood around 10:30 a.m. Sunday, when the unidentified assailant walked up behind him and asked for the time, police said.

The goon snatched a gold chain off the teen’s neck, but when the boy tried to retrieve it, the crook bit him on the hand, drawing blood, cops said.

After the bite, the thief demanded the youngster’s cellphone and followed the boy as he tried to run away, police said.

When they approached a nearby building’s lobby, the teen screamed for help, at which point the thief scampered off toward 10th Avenue, police said.

The boy was taken to Columbia Presbyterian Hospital in stable condition, police said.