Dear PoJo,

    As you and all of my fans might have guessed, I have a love for GRASS
PoKeMoN.  My favorites are NIDOKING, Scyther, Tangela and I am very fond of
Butterfree.  It is because of him that I am writing to you.  PoJo-YoU Da BeSt!

Lets take a look at Butterfree's stats:

Butterfree

70 HP

CC Whirlwind 20- If your opponent has any benched PoKeMoN, he or she chooses
1 of them and switches it with the defending PoKeMoN (Do damage before
switching the PoKeMoN)

GGGG Mega Drain 40- Remove a number of damage counters from Butterfree equal
to half the damage done to the defending PoKeMoN (after applying weakness and
resistance) (rounded up to the nearest 10)

Sad Parts:
Weakness to Fire
Evloves from Medapod and Caterpie
Mega Drain takes lots of energy

Happy Parts:
No retreat cost
Heals up to 30 (Pluspower)
Can switch the defending PoKeMoN
Resistance to fighting
It's common
Does as much as 50 damage (Pluspower)

As trc1188 said, Butterfree is a good PoKeMoN, but NOT against fire is what
he didn't say.  If it was any other type, especially fighting, Butterfree
would do GREAT!  Lets say, your opponent brings out a Mr.Mime. You can use
Whirlwind and leave it with only 20 HP left.  If s/he brings out a Staryu, us
Mega Drain and it's fainted.  Butterfree also does good against anything that
starts with "Poli-", Fighting and Kadabas.

Now remember kids,
I HAVE A PUPPY

Moo-oo-oo

                                                    From,
                                                    MoO-MoNsTeR