Rammus

Strengths

Powerball can be used as an effective escape mechanism.
Using taunt on a champion by your tower can cause the tower to attack your enemy.
Tremors and Defensive Ball Curl can be used late in the game to obliterate towers. If you're bogged down in a team fight, it is often valuable to break off and attack the buildings.

Passive · Spiked Shell — Rammus gains bonus Attack Damage scaling with his Armor and Magic Resistance.
Q · Powerball — Rammus accelerates in a ball towards his enemies, dealing damage and slowing targets affected by the impact.
W · Defensive Ball Curl — Rammus goes into a defensive formation, vastly increasing his Armor and Magic Resistance, and returning damage to enemies that attack him.
E · Frenzying Taunt — Rammus taunts an enemy champion or monster into a reckless assault against him.
Ultimate · Soaring Slam — Rammus hops into the air and slams down at a target area, dealing magic damage and slowing enemies. If cast while Rammus is in Powerball, Rammus knocks up enemies near the center as well.

A suggested 5-lane lineup built around Rammus, based on hero partnerships and role synergy — not win rate.