Well, I just wanted to tell you guys at mobafire of this awesome minigame. There are quite few rules that I'll explain. This is a CUSTOM GAME, DO NOT TRY IN REAL GAMES. Don't be stupid. PLEASE.

Rules:

Both teams need a Teemo (obviously)
You can't attack Turrets unless your team killed Teemo. In case you did kill Teemo, your team is allowed to attack a turret.
You can't protect turrets under enemy's attack
No champion can kill minions, but you can stand in a lane to get experience.
Everytime you kill a minion, you can't chase the enemy Teemo or defend your Teemo for 30 seconds.
You CAN kill monsters in the jungle, but you can't kill the Dragon or Baron Nashor.
You can't use Long Stealth champions (Evelynn, Twitch)
Summoner spell Fortify is not allowed.
Only 2 champions in both teams can use Clairvoyance.
Aura Items are forbidden, except for Abyssal Scepter, Emblem of Valour, Mana Manipulator, Soul Shroud and Aegis of the Legion
There can't be more than 1 taunt champion on a team. (It's either Galio, Shen or Rammus)
You can't kill Buff Monsters.
Can't buy wards.

About Teemo:

Teemos can't stop moving.
AP items that gives over 30 AP on Teemo ARE NOT ALLOWED. This avoids high damaging Blinding Darts and Noxious Traps.
Teemos cannot attack monters in the jungle, but he can stand in a lane to get experience
Teemos can build 1 Offensive Item, 2 Defensive Items and 3 Movement Speed Items. (For example, Teemo gets a Boots of Mobility, a Youmuu's Ghostblade, a Banshee's Veil, etc.)
Teemos cannot have 2 of the same item.
Atma's Impaler cannot be built
Teemos CAN'T build any item related to Pickaxe or B.F. Sword.
Only Teemos can buy and place wards.
Teemos can use as summoner spells Ghost, Exhaust, Flash, Smite, Rally and Cleanse.
Teemo cannot attack the other Teemo nor his defenders, and can only attack his chasers via abilities.
Teemos are the only champions that can attack turrets.
Everytime a Teemo kills one of his chasers, you and your team can attack an enemy turret.
Teemos cannot build Aura Items, except for Soul Shroud.
Teemos cannot stay inside his base. He gotta be in the jungle or in lanes.
Teemos cannot go back to base.
Teemos are the only champs that can kill Buff Monsters

IF ANY OF THESE RULES IS TRESPASSED, YOU MAY ASK FOR SUICIDE.

Roles:

Runner:

Teemo is the runner. You gotta run and avoid getting killed. That's pretty much it.

Hunters

These champions are trying to kill Teemo. They'll do anything they can to kill Teemo.
Hunters can use as summoner spell Exhaust, Ghost, Flash, Ignite and Clairvoyance.
It is better for hunters to take out the defenders first rather than trying to kill Teemo, as they can really soak up damage.

Defenders

These champions must defend Teemo. They're normally supports and tanks.
Defenders can use as summoner spell Exhaust, Heal, Clarity, Teleport, Clairvoyance and Revive.
They cannot attack the other Teemo. If Teemo dies, the Defenders must go back to their base and wait for Teemo to re-spawn

Look up at the champs on the teams.

Alistar and Kayle are defenders, since Alistar have a Knockup, a Knockback and Heal, while Kayle has a Heal, that is also a speed buff, and a slow.

Xin Zhao and Vayne would be Hunters. Xin Zhao has a great burst damage and can also dash to the enemy, also he has a Knockup, while Vayne has a tiny dash, but she has an incredible Stun and moves faster when enemy champions are nearby.

In the other team, Taric and Sona would be defenders, since Taric has a Stun, an Armor Buff and a heal, and Sona has a heal, a massive stun and a movement speed buff.

Nocturne and Veigar would be Hunters. Nocturne can quickly finish Teemo thanks to his Ultimate, Spell shield, AD buff and Fear. Veigar can deal huge damage with Dark Matter, and he has a giant stun.

Both Teemos would normally start with Boots of Speed, a Sight Ward and a Health Potion, with Move Quick as his first Ability

That's the game. It can be really fun trying to catch that little f*****, and rather pleasing to kill him. I hope that if you EVER play this game, you have some fun :).

See ya~