Background: Octopus vulgaris is a common marine animal that can be found in nearly all tropical and semitropical waters around theworld. It is a peaceful sea dweller with a parrotlike beak, and its primary defense is to hide through camouflaging adjustments. Bites from animals of the class Cephalopoda are very rare.Wedescribe a boy who was bitten on his forearm by an Octopus vulgaris. Observation: A 9-year-old boy was bitten by an Octopus vulgaris while snorkeling. There was no strong bleeding or systemic symptoms; however, 2 days later, a cherrysized, black, ulcerous lesion developed, surrounded by a red circle that did not heal over months and therefore had to be excised. Histologic examination showed ulceration with extensive necrosis of the dermis and the epidermis. A microbial smear revealed Pseudomonas (formerly known as Flavimonas) oryzihabitans. After excision, the wound healed within 2 weeks, without any complications or signs of infection. Conclusions: To the best of our knowledge, this case represents the first report of an Octopus vulgaris bite resulting in an ulcerative lesion with slow wound healing owing to P oryzihabitans infection.Werecommend greater vigilance regarding bacterial contamination when treating skin lesions caused by marine animals.