Modok is a member of the Vehicle Voltron Land Team, who can best be described as a "gentle giant." He pilots the Armored Equipment Carrier that forms the left forearm of Voltron.
Voltron: Defender of the Universe cartoon continuity
Vehicle Force sub-series
Devil's Due Publishing comics continuity
Modoc was one of several people chosen to pilot the machine named "V-15" by Galaxy Garrison, he and his team were first deployed after the original Voltron to recapture it until he received new orders to support Voltron.