The Saurian King is a colossal lizard that hammers fear home on his enemies.
Xyzzy is a giant Saurian Myrmidon, with fast speed and medium armour. He is the fastest boss in the series, as well as being tied second most armoured, being beaten only by Lord Blackburn and rivalled by Hi-Hi Enha.
Xyzzy also possesses a special area attack where he smashes the ground 8 times with his cybernetic hammers, dealing 100-150 damage on each swing. This attack hurts every unit in an area around Xyzzy, which is different between versions of the game. Within the Mobile Version, the area becomes as large as the whole map, yet barely beyond Xyzzy's melee range in Steam release, making him a much easier boss. Strangely, this attack is able to harm Ashbite and Bonehart, even though both of them are flying. When forced into melee, Xyzzy can catch soldiers with his tongue, swallowing them whole, effectively instantly killing them. Heroes are immune to this, although they are unlikely to survive Xyzzy's special area attack.
- Archmage Towers shine against Xyzzy, as he has both armour and high health. Since Xyzzy attacks from the northwest, it is useful to place Archmage Towers on Strategic Points which aren't needed for other towers on that path.
- With just four of them, three of which should be on the three points above the path, a resonable number of critical mass upgrades, and on top of any other towers used throughout the other waves, Xyzzy shouldn't even make it past the point where the two entry paths converge.
- The Battle-Mecha T200's Waste Disposal can slow him down tremendously, and the Wasp Missiles will follow him even as he dashes out of range.
- Heroes and soldiers are doomed against him, they are best used to delay his minions or to stall him as a last resort.
- Xyzzy is the first boss in the Kingdom Rush series to have armor/magic resistance.
- Xyzzy is also the fastest boss in any Kingdom Rush game.
- His area attack shakes the screen, if on a device that supports screen shake.
- His name is possibly inspired by the "magic word" of a video game cheat code of the same name. In addition, Xyzzy is the mnemonic used when calculating the cross product.