Panaque schaeferi is a freshwater species of fish from the Loricariidae family of South American armoured catfish. Panaque schaeferi is widely distributed throughout the upper Amazon (Solimões river) in Peruvian and Ecuadorian rivers, and has been observed as far down as Santarém, Brazil. Growing to at least 600mm SL, it is one of the largest, and likely 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' (due to its resemblance to the VW Beetle car), also L203 and LDA065 under the L-number code. Juveniles are often confused with Panaque bathyphilus and erroneously called L090c.