The Bell Gargoyles are the guardians of the first Bell of Awakening that is found in the tower atop the new church. The gargoyles are magically created creatures that oppose any undead who attempt to ring the bell, fighting any who attempt to cross the roof to gain access to the belltower.
It seems likely that they are a creation of the gods, as gargoyles can also be found in Anor Londo. In this case, it seems likely that they are meant as a test to prove the worth of any who would try and claim the title of Chosen Undead.
They wield large spears and breathe fire.