He appears as the sponsor of the renowned warband that fought at the Battle of Catraeth in the early Welsh poem.
John T. Koch considers Mynyddog Mwynfawr to be a place (meaning approximately "Wealthy Mountain").
Koch argues that Mynyddog Mwynfawr is a kenning or personification which represents Din Eidyn, Gododdin, or perhaps the entire Old North, and that Gwlyget, described as Mynyddog's steward, is the ruler of Gododdin.
The popular Welsh poet Richard Davies (1833–1877) adopted the name Mynyddog as his pen name.
Use of an adopted Welsh-language pen name was common among Welsh poets of his era.