I wouldn't, the tank is really too small for either. The porc can get especially nippy and aggressive, especially in a smaller tank. While I believe a 120g is a bit small for a dogface puffer, one would be a safer bet. For the most part a dogface is rather docile, but the porc has a tendency to get aggressive even in larger tanks. In captivity most dogface puffers will get to 10" maybe more, I have seen some a solid foot of rotund girth.