Slowbro

Although Slowbro is typically a dopey Pokemon, it seems to get a stroke of inspiration when the Shellder on its tail bites down hard.  It can't feel any pain because the Shellder is seeping poison that's like a pain-relief medicine.  If the Shellder on its tail goes off, Slowbro becomes a Slowpoke again.
Slowbro is like a Pokemon that isn't just slow in the video games, but slow when it comes to smarts.  The Pokedex makes Slowbro look like the stupidest dim-witted thing with a brain out there.  It's what makes it so likeable and cute.  Slowbro is a Pokemon with mixed up stats.  It's obviously a slow Pokemon.  It has considerably high Defense and Sp. Attack stats.  He has okay HP, Attack, and Sp. Defense stats as well.  It doesn't make Slowbro bad or anything, just a little different.  It adds up to a fairly useful Pokemon.
Slowbro has a good movepool.  He has lots of STAB moves.  He can learn Slack Off, which is a recovery move, meaning it restores HP.  He can use Heal Pulse, which is useful in Double, Triple, and Rotation battles.  If one of your ally Pokemon is low on HP, just fire this move at them.  It works out great.  Slowbro has a good movepool overall. 
He has okay abilities.  Oblivious means you can't fall in love with your opponent's Pokemon.  Moves like Attract will have no effect.  It's a fairly good ability, though not many people use this strategy.  Slowbro's other ability, Own Tempo, prevents it from being Confused.  Movves like Flatter and Swagger have no effect.  It's a good ability.  No more will you have to worry about hurting yourself in confusion.  Own Tempo rules.
So Slowbro is an okay Pokemon.  Not everybody's first choice, but an okay Pokemon overall.