Flapwicks are big ol' Zubat looking monsters that fly around and pause to screech every couple seconds. Every third screech has a slightly bigger hitbox than normal but all screeches do the same damage. Hitting a Flapwick makes it alternate between moving horizontally or vertically. Like spinners, these were meant to wander freely but I'm having trouble with the code for that but this Drillor style wall bumping works perfectly.
As for the Psybats, they took most of the code from Goorbs and basically flap in place until you hit them. When hit, they throw one of their four levitating rocks at you which do more damage than Goorb balls but don't bounce everywhere. Once all the rocks are gone, the bat resorts to feeble screeching like it's Flapwick cousin until you can take it out. The rocks will block everything but the Cut and Surge spells so you'll have to time your shots or switch over to a spell that can kill them.
