California police are circulating a caricature of a suspect who allegedly stole $500 from the artist who painted it.

"And no, we are not kidding", police said.

While working at a festival in downtown Riverside on 5 December, the artist was approached by the alleged thief, who requested a portrait of himself, according to police.

Once the artist finished, the suspect grabbed a money bag containing $500 that belonged to the victim, then ran away, leaving behind a cartoonish portrait of himself.

Riverside police note that the portrait "of course has exaggerated characteristics and features" but is sharing the image to seek information from the public.