Mouths would reasonably appear in all Star Wars material. This list contains appearances where "mouth" is explicitly described.
- Star Wars: Darth Plagueis
- Clone Wars Gambit: Stealth
- The Mandalorian Armor
- Therefore I Am: The Tale of IG-88
- Of Possible Futures: The Tale of Zuckuss and 4-LOM
- Rebel Dawn
- Mouth on Wikipedia