Apparently Wigglytuff has been to Waterfall Cave before... Chatot is a liar confirmed

Moment at 39:03 to 43:18 in Demifire's Pokemon Mystery Dungeon Explorers of Sky Playthrough Part 6 by Demifire Firestorm.

Demifire's Pokemon Mystery Dungeon Explorers of Sky Playthrough Part 6

Saved by Demifire Firestorm.