Annie - Tank
Shen - AP and Jungler
Kennen - AD
Cho'Gath - Support and Roamer
Rammus - Beefy DPS / Offtank

Why these champs?

Annie has an AOE stun, a long range auto-attack and even has a spell that increases her Armor and Magic Resistance as well as deal damage to those that attack her. This make her one of the best troll-tanks.

Shen has great AP ratios, and spams his spells to no end to trigger Lich Bane all the fkn time. He also has self-healing on his Q and protection on his W that scale with AP and are further empowered by this item build. Allowing him to be in close combat while sustaining himself. Rylai's, his Taunt, and Hextech Gunblade make sure you ALWAYS catch your target.

Kennen has a high baseline attack speed and has his passive to ensure you proc your W alot. His stuns are also excellent to deal consistant damage, and the tri-force will trigger alot with all his skill-spam. His movement speed is also through the roof, allowing him to constantly attack his enemies.

Cho'gath has extreme CC abilities which allow him to roam like a boss! Similiar to Alistar he runs around lanes finding opportunies to gank or to counter their jungler. His Feast ability allows him to live through a teamfight, and capped Cooldown Reduction allows him to CC as often as possible with buffing auras for your team, and crippling auras for the enemy. Can also lane excellent if roaming is unsuccessful.

Rammus. His passive means that every time he gets a chunk of armor, his AD increases. And combining this with his extreme mobile powerball, his taunt, and even his turtle form he makes for an extremely dangerous foe. Frozen Mallet, Ghost Blade, Atma's Impaler and Madred's Bloodrazor all have excellent synergy for him. Providing him with a non-stop slow to always attack his enemies, granting him even more AD through health, and providing protection with a very offensive nature. His attacks deal alot more damage then you think.