Flock

Fluttering Baffin
Location: South of the Forest and The Water Towers
Details: You can find the Fluttering Baffin on a platform located south of the forest and The Water Towers. They are extremely skittish, so it's best to approach them quietly.

EDIT: Thanks to Zapperlott who commented they found it "right next to Stonestar Meadow at Western Plaza (8)."

Spung Baffin
Location: Wetlands
Details: These Baffins emerge from the mud in the Wetlands when you move quickly over them. Be ready to catch them mid-air before they dive back into the mud.

Dappled Baffin
Location: Wetlands
Details: Similar to the Spung Baffin, the Dappled Baffin is easier to catch after the main game. Use the feeders around the Wetlands, especially the one between the three circles, to attract them.

Frilled Baffin
Location: Wetlands near the Circles
Details: These Baffins are rare and appear near the circles in the Wetlands. They are very fast, so you will need to chase them until they tire out before you can identify them.