The following belongs to Riot Games, creators of League of Legends.
When the prophet Malzahar was reborn in Icathia, he was led there by an ominous voice which thereafter anchored itself to his psyche. From within, this voice bestowed upon him terrible purpose, and though Malzahar was no longer tormented by its call, the voice did not cease its unrelenting summons. This baleful beacon's gentle flicker - now fastened to Runeterra - drew forth a putrid beast that ambled across a threshold it did not understand, widening a fissure between spaces which were never meant to meet. There amongst the haunting ruins of Icathia, Kog'Maw manifested in Valoran with unsettling curiosity. The spark which led him to Runeterra teased him still, urging him gently towards Malzahar. It also encouraged him to familiarize himself with his new environment, to the stark horror of everything he encountered on his journey.
The enchanting colors and aromas of Runeterra intoxicated Kog'Maw, and he explored the fruits of the strange world the only way he knew how: by devouring them. At first he sampled only the wild flora and fauna he happened across. As he traversed the parched Tempest Flats, however, he came upon a tribe of nomads. Seemingly unhampered by conventional rules of physics, Kog'Maw consumed every nomad and any obstacles they put in his way, amounting to many times his own mass and volume. The most composed of his victims may have had time to wonder if this was due to the caustic enzymes which stung the ground as they dripped from his gaping mouth, although such musings were abruptly concluded. When his wake of catastrophe reached the Institute of War, an enthusiastic Malzahar greeted him with an enticing prospect: taste the best Runeterra could offer…on the Fields of Justice.
- Icathian Surprise - When close to death, Kog'Maw becomes extremely fast and charges the nearest attacker. Within four seconds of charging, he'll explode, damaging everyone nearby.
- Caustic Spittle - Kog'Maw attacks faster. He also gains the ability to spit acid at his enemies. The acid will hurt them and weaken their armour.
- Bio-Arcane Barrage - Kog'Maw can temporarily hit people harder from a longer range.
- Void Ooze - Kog'Maw launches some kind of ooze at his enemies. The ooze will hurt anyone caught in front of it and leave a trail that slows anyone walking through.
- Living Artillery - Kog'Maw launches a living artillery shell at a target location. The shell damages anyone caught under or near it and lures Kog'Maw towards the area. He can fire off multiple shells in a short amount of time, but cannot fire endlessly.