Digi-Facts: To end up with the undesirable Champion level Numemon, a Rookie level Digimon must not meet the evolution requirements of any other Champion level Digimon it can evolve into. If you don't look up the requirements (either through a strategy guide or these days, the internet) and raise your Rookie Digimon without knowing what other Champion level Digimon you want it to turn into, then there is a very good chance you will end up with Numemon because you didn't meet the right requirements. All of Numemon's attacks revolve around bodily functions. Please don't make me explain them.