Another great item from my 11 year old son presented just as he wrote it.
This small object appears as a jade statuette of a dolphin, if thrown onto the the surface of water it has the following different settings(each with a different command word):
The pack dolphin:
This setting(18 h.p. a.c.5. 2 1d4 damage.) has the special property of having the same carrying capacity as a draft horse, it is however never slowed down by encumbrance.
Everything carried by the pack dolphin is protected from water and gets a +4 on all saving throws.
The riding dolphin:
This setting(h.p. 24, a.c.3,2d4+1 damage.) is large enough to carry a human of maximum size as a rider, it has triple normal dolphin swim speed(90".). It's rider is affected as if he or she were in the area of a airy water spell, it's rider's weight does not count for encumbrance when used as a mount.
The killer dolphin:
This setting(h.p.32.a.c.2,damage 3d6.) is used solely for combat, it does double damage when charging and takes half damage from cold and lightning.
Each setting can be used once a week for up to 24 hours at a time. If the dolphin is dropped to 0 or lower h.p. the statuette lies unusable for a week. After 9 total uses the figurine becomes inert.