Magrillo was a Lurker who lived in Vanezia.

Whilst living in the city of Vanezia Magrillo found the remains of a Rokathia black box and thought it a fallen star. The device sang to him, telling him how to build an opera house and an automatic orchestra. Magrillo built androids, whom he employed to abduct people from the city, whom he used to power the device. The device would transmit a mathematical equation into space.

When the Tenth Doctor and Rose arrived in Vanezia, they met Frederico Gobbo, and came across the black box device. The Doctor made the device overload and explode, killing Magrillo and allowing all the musical ability the device had absorbed to be transferred to Gobbo's mind, giving him musical talent. (COMIC: Opera of Doom!)