Titchy Gren is a very small humanoid (of a different race to the Gyrm) and the leader of the Brotherhood of Blood covenant.
He is a worshiper of Nahr Alma, the God of Blood. He recruits those who wish to worship Nahr Alma.
"Titchy" is a word that means "very small", and "Gren" is a Swedish word for "branch" (though that may not be relevant).
If aggroed, Titchy Gren will attack you with his scythe but predominantly uses hexes.
He has no interest in those who do not seek to spill blood and will not allow you to join his covenant unless you have a Token of Spite, proof that you have invaded someone else's world and killed them.