http://www.moghroith.org/name.html
http://en.wikipedia.org/wiki/Mog_Ruith

The Mogh Ruith/Tlachtga Cycle at http://www.maryjones.us/ctexts/index_irish.html :-
The Beheading of John the Baptist by Mogh Ruith
The Executioner of John the Baptist
Verse on Mogh Ruith, Book of Leinster
The Genealogies of Mogh Ruith The Genealogies of Mogh Ruith
Tlachtga Tlachtga: genealogies
Tlachtga (Müller-Lisowski edition) Tlachtga (Matthews translation)
Tlachtga (Gwynn edition) Tlachtga (Gwynn translation)