Who needs a Soraka or a Sona for a support when you have Kog'Maw? Kog'Maw,with that slow, will help dominate any game. Soraka may be able to reduce Magic Resist,but Kog'Maw reduces Magic Resist AND Armor. Sona may have a stun,but who needs a stun when you can just slow them? Slowing gives you that excited feeling when your chasing an enemy slower than a snail. With that, I present SUPPORT KOG'MAW.

Pros
- Kog'Maw is normally squishy,but this build fixes that.
- Fun to play.
- That feeling when you pwn as a support after your team rages about Kog'Maw not being a support.
- Q and E helps kill someone really easily.
- Can do decent damage with W.
- Fed as hell off of assists.

Cons
- Slow can be dodged.
- If you fail,you will be raged at.
- You don't do as much damage as a Kog'Maw with a regular build.
- Not recommended for a serious game.

Boots of Mobility - Run around and help your team. The speed also helps you blow someone up after you died.
Rylai's Crystal Scepter - This will help you slow runners with your R.
Everything else - Extra stats for your team

Caustic Spittle - After one point into every skill, you want to max this out first. This will reduce your enemy's Armor and Magic Resist even further which will help your team kill them faster. The attack speed will help you far

Void Ooze - After Caustic Spittle, max Void Ooze. The more points you have in Void Ooze,the more you slow them. The more you slow them,the easier it is for your team to kill them. Void Ooze is also handy in running away.

Bio-Arcane Barrage - Max this skill out last. Your team will be the one doing the damage so you won't need it much.

Living Artillery - Add a point into this skill whenever you can. This skill is handy for checking bushes without having to run into them. It can also be used to kill some people at really low HP.

Recommended
Flash - The best summoner spell in my opinion. This skill lets you escape many things. You can escape a gank to avoid dying. You can also escape a team fight if your dying. This skill can also be used to get kills if no one else can.
Teleport - This skill is a fast way to get to your team instead of walking.

Others
Clairvoyance - You don't really need this since you have your R,but it can be used early game.
Heal - You have no heal to protect your team so you might want to get this.
Exhaust - Another slow just in case your E is on cooldown.

Buy wards to ward wherever you think the opponent is going to go to often. Some places to ward are baron,dragon,and bushes.

Try to go either bot lane to top lane with someone that could do really high damage. My personal favorite laning partner is Vayne when I use this build. Use your Q and E on the enemy and let your partner kill them. Help out with your W and R just in case you partner can't kill them alone. After you get your Boots of Mobility,go around helping other lanes when your lane is taken care of. During a team fight,use your Q and E on the enemy and harass with your W and R from a distance.

If you read the whole thing,there's only one thing for you to remember. Don't use this guide in a SERIOUS game.