Dread Stalker

The dread stalker has a mana organ (the pituitary gland) that allows it to become invisible when conscious. Only slightly larger than a wolf when visible it resembles a small, duncolored hyera with almost reptilian features.
Despite its invisibility it prefers to pick off the lone straggler of a party in caves or tunnels going for close combat attacks and avoids large parties.
*Which hex the creature is in: Hearing-2
*Attack: -6
*Defence: only if Hearing-2 made and at -4
The mana organ is destroyed if the head receives 1/2 HT or more.