Polymorph, Greater (Wyvern)

The target creature becomes a wyvern. It gains a +4 size bonus to its Strength, a –2 penalty to its Dexterity, and a +4 natural armor bonus. Its movement speed is reduced by 10 feet. It also gains one 1d8 tail slap attack plus poison. Wyvern Poison: Sting — injury; Fortitude save (DC 17); frequency: 1/round for 6 rounds; effect: 1d4 Constitution damage; cure: 2 consecutive saves.