Gardener Thornelia
She was the family gardener and wife to the groundskeeper, Turfington.  It was documented that she was also a herbologist but the citizens of Perilous Downs regarded her as a witch.  Through some dark method she was able to splice all the world's deadliest plants into one extremely loyal carnivorous hybrid which then grew in abundance.  Their diet was a secret but McMorbidly Manor never had infestations of any kind.  Not one weed, bug, or small wild animal dared to show its face while her plant children were around the garden. In spite of their ghastly guard duty, they always had time for kisses from “mumzy”.