Slowking

Type Tier
Water / Psychic BL
Statistics
Stat
HP
95
393
Atk
75
248
Def
80
258
SpA
100
298
SpD
110
318
Spe
30
158
Name Item

Special Attacker

Leftovers
Moveset
~ Surf
~ Psychic
~ Thunder Wave
~ Rest

Does it look familiar? It's just like Slowbro. Paralyze things, attack as you see fit.

Other Options

It can Reflect to boost that average Defense, and Zap Cannon is fun to attack and Paralyze. Slowking can Fire Blast to hit Grass-types and Steels. Ice Beam covers Grass Pokemon as well as Dragonite. If you want to give Blissey and Snorlax a run for their money, consider DynamicPunch.

Opinion

Essentially a weaker Slowbro. Since every Special attack (except for Dragon attacks, but those are out of question since nobody uses them) will either be super-effective or not very effective on him, the Special Defense really doesn't make much of a difference—most strong Thunderbolts kill Slowking in 2 hits just like Slowbro. However, Slowbro can eat a good deal of Physical hits, while Slowking cannot. It's funny how simply swapping 2 stats vastly change the usefulness. Slowking is still good, but Slowbro is just better.

Counters

Slowking is fairly sturdy on the special defensive side, so the usual Electric-types won't destroy it as quickly as they do other Water-types, but eventually they will win. Exeggutor and Celebi do a good job of wearing down Slowbro, but note that Celebi can do little more than Leech Seed it, as its standard set only has Psychic as an attacking move. Snorlax and Blissey, as usual against special attackers, stall Slowking out, and the former sweeps with Curse. Starmie's Thunderbolt has a bit of a hard time taking it out, but Recover will make sure Starmie lasts long enough for it to do so.