After the extensive research done by Vel'Koz, the Void put together an Abomination; a Chimera, as they call it. The greatest masterpiece the Void has ever created, based off the deadliest and strongest animal species Vel'Koz has researched on. Three serpent heads, one Eel, one Snake, one Lizard, on the body of a head of a whale, with two tails similar to that of a scorpion's, completed with the tentacles of a squid for movement on land and in sea. Lastly, they gave it a name. Gal'Zor, the Abomination of the Void was born.
Gal'Zor's main purpose is to demonstrate the power of the Void. Unlike his counterparts, Gal'Zor was created and transported to Runeterra to spread fear among the denizens of Valoran. Bent on mass destruction and widespread fear and panic, Gal'Zor looked on towards the League of Legends, and decided to start his own form of mayhem there.
"Now that he has been created, there's no stopping his destruction." -Vel'Koz, Eye of the Void