Drowzee and his evolutionary form, Hypno, are known as Hypnosis Pokemon. They're of the Psychic-type, and as such, have highly advanced brains. The combination of these two factors should show one obvious fact - the Drowzee line hypnotizes its opponents.
It's diet is a mystery. Many believe it feeds on dreams, however, this is an impossibility. It may use dreams for other needs, or for its mental wellness, but it's fairly obvious dreams cannot be used as food. It's more likely that the line is herbivorous - feeding on berries, shrubs, and other plants near the ground. The trunk of a Drowzee supports this theory, as, for many four-legged herbivores, trunks are used to pluck and hold plants. It was likely that this was its original purpose, but as Drowzee adapted over time to its current, bipedal form, this adaptation became unnecessary, as it could just as easily use its hands.
The how the Pokemon's hypnosis is a simply one - being a Psychic-type, it's frontal lobe is larger than most animals, and it uses this to its advantage by transmitting waves through their eyes. The mystery is exactly why it uses hypnosis. The most simple explanation is that it hypnotizes "prey" and feeds on their dreams while they are in a prone state. "Energy" that is consumed by Ghost-type Pokemon is somewhat of a mystery to us, but it's very likely that dreams are made up of similar energy. Good dreams cause a positive effect upon consumption; nightmares a negative one. Perhaps energy is really emotion, and eating dreams is simply tapping into the emotion of a prone being?
Hypno is another mystery. The mane is larger in females, making it seem they are the dominant of the two genders, unlike most species. Of course, the pendulum created, or obtained, it also interesting. The reflective properties seem to transfix the eye, and the effects of hypnosis seem to hinge purely on eye contact. This much is obvious - it causes its prey to look upon its pendulum, then look into its eye. But where this item is obtained baffles scientists to this day.
Hypno, and to a lesser extent Drowzee, are very interested in human children, and possibly the children of the young from other species. There are even some reports of the Pokemon hypnotizing a child and kidnapping it, never to be seen again. Many theorize that, as children are more innocent, and "pure," their dreams are better for the creatures. This is insubstantial, as it's nearly impossible to measure the flavor of a dream.
Drowzee are found in grasslands, usually nearby cities, due to the lack of large predators. Few Hypno have been found in the wild, but it's theorized they would live in urban areas, due to their physical frailty and penchant for human children.
Other than for breeding, the line entirely solitary. It is unknown how their young are raised, or if there is a family structure, as only domestic Drowzee and Hypno have ever given a documented birth. It's likely that the line's pre-evolution, if it indeed has one, would be a small, brown quadruped; one with a long trunk that it uses to feed in thick brush, as to avoid being seen by both predators and humans.
The Drowzee line is a mysterious one indeed, but other than a few interesting quirks, it's simply a matter of time before we discover the Pokemon behind the legends. I'm Johnny One-Three-Nine; join me again next time for another edition of PSA - Pokemon Scientific Analysis!
toadster101
Bravo! *does a Hypno cry*