Ah and Ung are two dragon-like creatures who appear both in Eastern Mind and Chu-Teng. Ah is green, Ung is red. They appear as gatekeepers in both games.
They consider themselves to be intelligent, and above other creatures in Tong-Nou, and are unfriendly to lesser creatures. They enjoy riddles and other intellectual games, and are also very fond of alchemy.
In Eastern Mind, their job is to guard the Palace of Dreaming, Ping-chao. They stand guard outside the entrance of the palace, and appear before the player to give them a riddle. If answered correctly, the player will be allowed to enter the palace. If not, they will be driven away.
Inside the palace, they can be found chatting underwater in one of the rooms. They discuss the possibility of creating gold, and leaving their job in the palace.
The dragons appear in Chu-Teng, once again as gatekeepers.
It seems as though their attempts to create gold were successful, as their both appear completely clad in gold in this iteration.
They guard the doorways in the White, Red and Yellow Roads that lead to unsafe spaces outside of Chu-Teng.