Outland Beastmaster with Millisaurs is a Hired Guns & Hangers-on kit. Games Workshop list it at £49.50.
More Hired Guns & Hangers-on kits
Luther Pattern Excavation Automata "Ambot"Hive Scum'Jotunn' H-Grade Industrial Servitor OgrynsKal Jericho and ScabsOzostium Aranthus, the Divine PrinceUnderhive Hangers-onThaetos 23-2, Wyrdlock Bounty HunterWasteland Giant RatsAshwood Stranger, Outcasts LeaderRex Spires and Estus JetNecromunda: Brute Handler & Chem DealerGorshiv Hammerfist, Bounty Hunter