The owner of this talisman gains +10 temporary HP.
Once the temporary HP is depleted, the player immediately suffers -2 CON. This effect is permanent until removed by remove curse, limited wish, wish, or similar.
The talisman's curse is single-use. Once the -2 CON has been bestowed on a player, the talisman is neutral and may be treated as nonmagical jewelry.
Tribal skull by Isidoro Ambasch on OpenClipArt.org. Creative Commons cc0.