i know we've moved on but i spent a while writing it before 10 pages popped up :/
To all those who doubt mun'na will evolve into drowzee I think I may have an explanation of how this could occur:
Mun'na was like all the other baby pokemon, he was innocent, carefree and loving. Each day before he went off to pokeschool his mother told him “mun'na, don’t go near anyone who has spotted brown legs, there very dangerous.” The baby mun'na would always reply “ok.” And would skip merrily to school. Mun'na excelled in his courses and was very proud of himself and he was happy in every way, except one. He felt he didn’t belong anywhere, as if he had no friends and his mother didn’t care. He noticed his mother disappearing for long periods every so often, but he thought nothing of it. One day he had a terrible day at school, all the other mun'na laughed at him and called him names because he did badly on a test because he forgot to study for it. On his way home, he dreaded telling his mother, and would be very happy if she was gone. On his way home a man with brown spotted legs, and a yellow torso confronted him. Mun'na knew his mother told him to stay away from these men, but at the time he felt so bad he thought nothing of it. The man with the spotted legs said “hey kid, want to eat some dreams with me?” mun'na was scared at first because he did not know what eating dreams was, so he replied “no” and went home. His mother was indeed gone when he was home and when she got home she didn’t berate him at all for doing poorly on his test, but she just went to bed. Over the next few days this same string of events happened, starting from the mysterious man confronting him, and ending with his mother coming home late and going straight to bed, the only addition being that every day the man would try to convince him, even calling him a coward and telling him that eating dreams was harmless. Over the weeks this pattern continued, the mun'na noticed his mother start to develop brown legs and her torso became a sickly yellow color just like the stranger. The next day he decided to try eating dreams. After school he went to the man with 3 weeks worth of allowance, and mun'na bought all the dreams he could. When he got home he locked himself in his room and nibbled on the first dream, he felt nothing at first so he ate the whole thing. After mun'na ate the whole thing, he felt elated, it was the best feeling he ever had, nothing could compare to the ecstasy he was experiencing. Eventually he ate all the dreams, gorging himself when he had a bad day or the money for it. After a while he began searching his mother’s room for stuff to sell for his next meal of dreams, he found a large batch of dreams in his mother’s dresser. When he graduated school and moved on. he started to notice his legs turn brown and his torso yellow, but the words of his mother were long forgotten. After a while he moved in with the stranger, and the stranger, in a bout of dream induced high, said hey lets catch someone, so we can keep harvesting their dreams, and so mun'na and drowzee kidnapped a human, and kept eating her dreams. After a while mun'na began to realize that he was exactly like drowzee, but this didn’t bother him, and eventually he forgot he was mun'na. from that point on he was just drowzee, and he has been drowzee ever since.