The Highbeast pygmy shrew tribe resided on the cliffs immediately north of Fort Marshank. They captured passing creatures and used them to take care of their children, called Squidgees. These pigmy shrews were led by their ruler Queen Amballa. Martin, Rose and Grumm Trencher were captured by them after escaping from Marshank. Martin ended up saving Amballa's son Dinjer from a gannet and thereby gained freedom for him and his friends and a hedgehog named Pallum. The highbeasts became their friends and helped to defeat Badrang in the battle of Marshank.
The Highbeasts appear in Martin the Warrior.