Tsuchinoko Dumplings are rare items that are most commonly found by healing the Tsuchinoko of poison and letting it escape, but there are three of them in various places in the world, although only one can be collected during the normal game-play: City of White Nights, Dragon Lair Cave in Kelvin's hallway and Distortion Corridor. Tsuchinoko Dumplings will follow you in a New Game+.