In an ongoing occasional series, previous ShukerNature posts have documented a number of once- and still-controversial forms of Chimpanzee – the Pygmy Chimpanzee or Bonobo, the Koolookamba, Ufiti, ape-man Oliver, and the Bili Ape. None, however, is as bizarre as this series' latest example – the little-known yet truly extraordinary spiny-backed chimpanzee reported from the Democratic Republic of Congo. The only information concerning this anomalous anthropoid currently known to me is a short account that appeared in Philippe Coudray's self-illustrated book Guide des Animaux Cachés (2009). According to Coudray, a member of a unit from the United States Navy who wishes to remain anonymous has claimed that during a mission to the Democratic Congo sometime between 1997 and 2002, the unit's team encountered 13 bipedal chimpanzees that were attempting to kill another animal. Standing 4.5-5 ft high, they were uniformly grey in colour, but by far their most distinctive feature was the series of spines running down each chimp's back, which stood up like porcupine quills whenever the chimps became agitated. Coudray also stated that the team actually shot a three-minute video film of these extraordinary apes, but that it remains a military secret. The precise location of this sighting is unknown, but as the team was from the US Navy and the Democratic Congo is virtually landlocked, it may have been somewhere close to Lake Tanganyika. The possession of genuine spines by these apes seems highly improbable, but perhaps they sported distinctive manes or even erectile tufts of hair that superficially resembled spines. Moreover, manes have also been reported from certain other bipedal crypto-primates, including the Batutut of Borneo (closely resembling the Sumatran Orang Pendek), the brown-furred Congolese Kakundakari, and the Central American Dwendi. Indeed, were it not for the chimps' grey fur, they might even have been one and the same as the kakundakari, although kakundakari eyewitnesses generally claim that this latter entity is humanoid rather than anthropoid in form, and smaller than the spiny-backed chimps. Among known primates, the only species that can in any way be described as spiny is a small loris-related African prosimian known as the potto Perodicticus potto. Its neck bears a series of small tubercles covering its elongated cervical vertebrae, which have sharp points and almost pierce its skin, and are utilised as defensive weapons. Needless to say, however, these do not even begin to compare with the quills described for the spiny-backed chimps discussed here. The bipedal nature of these chimps is very noteworthy too, as chimpanzees do not normally exhibit such behaviour as a habitual activity. With so little information and no hard evidence to examine, and not even any eyewitness names to pursue, however, there seems little else that can be said in relation to the Congolese spiny-backed chimpanzee. Could it simply be a hoax, or a figment of poorly-viewed or imperfectly-reported observations? Or might there really be a singularly astonishing strain of spiny chimp out there, still awaiting formal scientific disclosure - a veritable chupacabra chimpanzee, in fact?!!