Trex crown is an item that normally is level 100 or great, but about 1 in 5 times will be level 99. It's only real use is adding stats so characters do not need to always be under the influence of giant strength and similar spells.
This is what identify reveals about this item:
Object 'T.rex crown' is type armor, extra flags hum magic nodrop.
Weight is 13, value is 2500000, level is 99.
Armor class is 19.
Worn:Takeable Head
Affects strength by 5.
Affects dexterity by 5.
Affects intelligence by 5.
Affects wisdom by 5.
Affects constitution by 5.
Affects armor class by -10.
Affects hit roll by 12.