Digi-Facts: Your Digimon's weight plays a factor when it Digivolves. Some Digimon require a specific weight value and other don't, but generally if your Digimon is too fat then it will likely Digivolve into a Digimon who looks and has a high weight value. Be it a glitch or not, but every time I had the Rookie level Penguinmon I did not train it at all and just fed it anything it could eat and it eventually turned into the Champion level Whamon. Why? Just to see what would happen. Also, Whamon is obvioulsy based on a whale but the one you get is about the same size as you. There is a NPC (non playable character) Whamon that you meet sometime in the game who is much larger that shows the actual size of Whamons.