Here is the full list of all 12 Pirate Pop Plus achievements.
Used treasure map with "X marked the spot"
Slightly dented spyglass, property of Bubble Pirate
Delicately fragile golden bubble, looks expensive
Comical inflatable hook. Small hand grip inside
Old wooden leg, one careful owner
Severely worn and tattered pirate flag
Cannonball made from solid gold (yeah right!)
For the sailor who sees no evil
Extremely aggressive (and sarcastic) parrot
Worn glasses, left lens is from milk bottle
"Property of Dave" embroidered on side
Rusty old key, opens Davy Jones' Locker