Beautifly

Despite its graceful looks, Beautifly can get a bit aggressive at times.  If it's disturbed when collecting pollen, it'll jab anything it sees as a foe with its long, thin mouth.  If you want to see one, just leave a potted flower by an open window.
In the first two games Beautifly appeared in, which were Pokemon Ruby Version and Pokemon Sapphire Version, this was one of the Pokemon that you can easily find near the beginning of the game.  Unfortunately, this means that it has low stats.  Low HP, low Defense, low Sp. Defense, low Speed- Yikes!  It has okay Attack stats, and its highest base stat- Sp. Attack.  However, it only has a base of 90, meaning it isn't exactly the strongest.  Low stats doesn't make Beautifly the most useful Pokemon.
Beautifly has some decent moves.  It can use Giga Drain.  It's a great move.  It has a good STAB move called Silver Wind.  It doesn't have the highest base power, but there's a good chance it might raise all of your stats a little bit.  It can also use Quiver Dance, which makes your Sp. Attack, Sp. Defense, and Speed stats.  If you can manage to use it a couple of times in battle, it'll make Beautifly a bit stronger.  Quiver Dance works out for any Pokemon that can learn it.  If you want to give it a strong move, try using Hyper Beam.  It can use Morning Sun, which restores HP.  If you use Sunny Day, making it Sunny in the battle, restoring more HP when you follow Sunny Day with Morning Sun.  Beautifly doesn't have the biggest movepool, but at least it has some good moves.
Beautifly's ability is Swarm.  It ups the power of Bug-Type moves.  Not too bad of an ability- Beautifly needs all the help with its stats that it could get, and the ability does just that.
To be honest, I love Beautifly's design- but it just has low stats and all that.  It could use some improvement.