Beach Oyster is a Legends of Idleon item: dropped by 1 monster, quest reward. Hold down to summon a bunch of Summer Monsters, and get a random Pearl!

Beach Oyster | Idleon Toolbox

Hold down to summon a bunch of Summer Monsters, and get a random Pearl!

Beach_Oyster

Hold down to open for a random reward! Or, hold down for a LONG time to open them faster.

Clear the beach of all these 'Out of Towner' monsters, namely 5 Plasti Dougs and 5 Mr Blueberry's