Zapple is a character who appears in Shantae and the Seven Sirens.
Zapple has a keen eye for out of place details. She's the first of the Half-Genies to notice that something is off about the Sunken City and Half-Genie Festival. It doesn't do her much good, however, as she's captured during the performance like all the rest.
She's also slow to trust others. Originally, she suspected Shantae to have kidnapped the other half genies, once she revealed that she hadn't been taken alongside them. However, she also trusted Plink and Vera's judgement, and was willing to give her power to Shantae to aid in her battle against the sirens.
Her dialogue implies that she is Armor Town's protector, but it is never outright stated.
She spends the rest of the game in Armor Town, and teaches Shantae the Spark Dance when given a Fusion Stone.