Shamrock
From Smurfs Wiki - Smurfology
A shamrock is a three-leaf plant that grows rather plenteous on the Emerald Isle. In "Shamrock Smurfs", Greedy had used these plants to create a stew that turned him into a leprechaun.
In Vic George's Smurfs fanfiction series, Tapper wears one on his hat for good luck.
