Large mammalians, Trellbats are adapted to hang from the cavern walls and eat the fungi.
They have an insectoid face, with four crushing mandibles to break up the fungal masses and rock.
They are slow moving, with a slow metabolism. They take seven years to grow to their full size, with a wingspan 6m across, and weighing 60kg.
Trellbats give birth sexually and ovoviviparously, and the offspring (born singly) lands on a pouch between its mother's hind legs.