[Murugan...signify a brave warrior capable of killing evil beings to save the devoted.
Sangam Tamil literature
Tolkappiyam, possibly the most ancient of the extant Sangam works, dated between the 3rd century BCE and 5th century CE glorified Murugan, " the red god seated on the blue peacock, who is ever young and resplendent," as " the favoured god of the Tamils."
Sangam Literature mentions Murugu as a nature spirit worshipped with animal sacrifices and associated with a non-Brahmanical priest known as a Velan, a name later used to refer to the deity himself. The worship of Murugu often occurred in the woods or in an open field, with no particular associated structure. The rituals practiced included the Veriyaattu, a form of ritual-trance-dancing, which is still a common part of Murugan worship in Tamil Nadu, Kerala and Malaysia. Murugu was believed to hold power over the chaotic and could be appeased by sacrifices and Veriyaattu to bring order and prosperity.]
This is not to say that Morrigan "mhor rheagan" great queen, and Murugan are linked, but the info. is interesting. More at Wikipedia Murugan, with the warrior riding a peacock with lady friends.