What are the chances to get a Obujos' Shell at his treasure chest?

Question

Just like the top, What are chances to get a Obujos' Shell at his treasure chest?

Answer 1

The following statistics of the items obtained by using the treasure chest outside of Obujos' lair 23 times.
 

Item	Amount	Percentage	Tries to get 1
Usual items* +  Giant Shimmering Pearl (Green)	20	86.96%	2
Usual items* +  Obujos' Shell	3	13.04%	8

*Usual items:  Trophy of Obujos,  30 Platinum Coins,  Deepling Staff,  Guardian Axe.

Source: TibiaFandom