now, we all now Wobbuffet is a little derpy, however, there is something about it you may not know.
first of all, here are the Pokédex entries for Wobbuffet:
"It hates light and shock. If attacked, it inflates its body to pump up its counter strike."
"To keep its pitch-black tail hidden, it lives quietly in the darkness. It is never first to attack."
"It order to conceal its black tail, it lives in a dark cave and only moves about at night."
"Usually docile, a WOBBUFFET strikes back ferociously if its black tail is attacked. It makes its lair in caves where it waits for nightfall."
"It desperately tries to keep its black tail hidden. It is said to be proof the tail hides a secret."
Figured it out yet? no?
to summarize the Pokedex's points:
-Wobbuffet's tail is VERY important to it. and it will do seemingly anything to protect it.
-its main move is to inflate its body to counter attacks.
Now, from this, i conclude that:Wobbuffet IS the black tail, and the the large blue body is a decoy, an inflatable punching bag for enemies to attack so the tail stays out of harm's way.
you will never be able to look at a Wobbuffet the same way again.