Lucky implings are a type of impling that can be caught in the Impetuous Impulses minigame, and are located throughout Puro-Puro and Gielinor. Players need at least 89 Hunter to capture this type of impling with a butterfly net or a magic butterfly net, or 99 Hunter to capture it barehanded.
Looting a lucky impling gives players one roll on the drop table of an easy, medium, hard, elite, or master clue scroll. There is an equal chance of rolling into each tier's clue scroll table. 
At current Grand Exchange prices, catching a lucky impling gives 54,560 worth of loot, on average.
The chance of a Lucky impling spawning in Puro-Puro is 1/301. In Gielinor, the spawn rate is 1/101. These rates make the Lucky impling about nine times rarer than a Dragon impling in Puro-Puro, and ten times rarer in Gielinor.