Goffar, known as Goffar the Pict as an identifier, was a king of Aquitaine circa 1000BCE according to the pseudo-histories of Geoffrey of Monmouth. In the myths surrounding Brutus of Troy's occupation of Britain, he led the Poitevins to war against Brutus' fleet. Although he sent messengers under a certain Himbert first, they got in a fight with Corineus, Brutus' general, over royal property and all of the messengers were brutally killed.
After a battle at the mouth of the Loire, the Trojans marched up the Loire through Goffar's dominions until they reached the territory of the Turones. There a battle was fought against troops given to Goffar by the 11 other kings of Gaul, and won, founding the city of Tours named in honor of Brutus' nephew Turnus, who died fighting.
This idea probably comes from Nennius' confusing passage in his Historia Brittonum: "he was exiled on account of the death of Turnus, slain by Eneas. He then went among the Gauls and built a city of the Turones, called Turnis [Tours]". Nennius is correct that the city is named after the tribe, not the similarly named person.