An 11-year-old bioy was sprayed with silly string in a day time attack.
Police are appealing for information after the incident in Morecambe on Saturday.
It happened between 3pm and 4pm outside Pound Fever on Euston Road when the boy, who was with a friend, was walking through Morecambe town centre carrying an owl.
The boys were approached by a large group of teenage boys who began to spray them both with silly string.
The victims ran away but the teenagers have then gave chase, punching one of the boys in the face.
PC Ben Hanley said: “This is an unusual incident which has occurred in broad daylight in the middle of the afternoon so I would appeal to anybody that witnessed it or with any information about those responsible to come forward.
“The motive for the offence is unclear at this time but it is possible they were trying to steal the owl. The use of the string has clearly caused the owl some distress but fortunately they managed to keep it safe and the boy was not seriously hurt.”
Anyone with any information should call Lancashire Police on 101 quoting crime reference BB1203964.