The Mangler is a giant crossbow built by Hal and Ingvar at the beginning of the Invaders to give the Herons an edge against Zavac and his pirate band. This crossbow is extremely hard to load and only Invar can do it alone. However as a last resort, Ulf and Wulf (the twins) can load this together.
The Mangler has a range of three hundred metres, however, it's practical range is around 150 metres. It is immensely powerful due to its great size, strength and fineness of it's crafting. It is Ingvar's job load it as only he, an possibly Thorn, has the strength to load it. Ingvar uses a crank to pull back on the heavy cord to load the bolt. Hal's job is to accurately aim, for it is only he who will be measure and estimate accurately the distance, trajectory and so forth.