Panaque schaeferi is a freshwater species of fish from the South American armoured catfish family Loricariidae. Panaque schaeferi is widely distributed throughout the upper Amazon in Peruvian and Ecuadorian rivers, and it has been observed as far down as Santarém, Brazil. Growing to at least 60 cm SL, it is one of the largest, and likely one of the heaviest species of Loricariid. It has been known in the aquarium trade since at least 1996 under various names such as 'Titanic pleco' and 'Volkswagen pleco', in addition to L203 and LDA065 under the L-number code. Juveniles are often confused with Panaque bathyphilus and erroneously called L090c.