Bayleef (the Leaf Pokemon) is an exceptionally rare Grass-type Pokemon found among grassy fields within the Johto region. Though more defensively-minded than other starter Pokemon, Bayleef are valuable fighters that can certainly put up a decent fight with their potent Razor Leaf and Magical Leaf attacks. Even if they can't hit very hard, though, you'll certainly be glad to have them around in a Multi-Pokemon battle; after all, it only takes a single whiff from their neck leaves to pump even a lazy Slakoth full of vim and vigor!
The members of the Chikorita family are unique in that their cellular structure, while primarily plant-like in composition, demonstrates features found only in animals. For one thing, the members of the Chikorita family possess distinguishable organs, such as a heart, stomach, brain and lungs, which plants obviously do not possess under normal circumstances. Secondly, these creatures possess animal-like forms that, aside from granting them advanced mobility for plants, allow them to deliver punishing physical blows with attacks like Body Slam later on in life; this is only surprising when one considers the fact that the only other plants capable of learning the attack are Tropius, and even then only because of their large size and similar body construction. From what can be told from genetic analyses, the answer behind these features is truly stranger than fiction: The members of the Chikorita family represent the only known case of animals turning into plants through natural evolution. From what can be told, it appears that the members of the Chikorita family mutated eons ago from herbivorous animals into plant/animal hybrids in order to adjust to local food shortages; as plants only need sunlight, water and a limited supply of nutrients for survival, such a drastic change does make some sense, if only by a stretch of the imagination. The reversal does not work, however, because advanced animal traits would take far longer to naturally develop within similar creatures than their genetics suggest; as such, the previously-mentioned hypothesis stands as the only plausible explanation.
While Bayleef share with Chikorita the ability to detect temperature and humidity with their head-leaf and are mostly dependent upon it for offense, they are aided in photosynthesis by the presence of extra leaves on their necks. The curled-up leaves, though seemingly brittle, are actually quite sturdy and resistant to damage; they are designed as such because each curled-up leaf is protecting a small tree shoot (each of which has grown from a seed present on Bayleef since their days as Chikorita). These tree shoots act as mobile energy reservoirs that gradually collect solar energy and photosynthesize it for the benefit of Bayleef, accelerating their development into adults; at the same time, however, the shoots are parasitic and radically alter the aroma given off by Bayleef. Instead of a calming smell, these shoots release a spicy, potent scent that stimulates brain and muscle activity to an exceptional degree, reviving unconscious or otherwise downed individuals with surprising effectiveness. Unfortunately, this aroma also has the effect of energizing nearby life forms without prejudice, potentially exciting opponents and placing Bayleef at a significant tactical disadvantage. While grim determination can help overcome this defect, the only sure-fire way one can take advantage of this situation is to place Bayleef in the company of other Pokemon, namely within a Multi-Pokemon battle; though somewhat unorthodox, combining a Bayleef possessing a technique like Reflect with an offensive partner can make most opponents squirm if they can't acquire a significant type advantage.
Though they might not be very useful for delivering offensive beat-downs, Bayleef are still powerful fighters that can give trainers a unique taste in defensive battling. With techniques such as Reflect and Stun Spore on their side and a wicked Magical Leaf attack that can easily down weaker foes, these creatures can certainly weather the storm in most battles until they finally gain some significant offenses upon evolving. If you prefer an enticing smell over a relaxing one, though, don't worry about battling with them too much; once theses critters evolve, it will be a trip back to the land of relaxing fragrances again, so grab all of the vim and vigor you can while you still have time!