So, in a typical fantasy world, mages and wizards have discovered a ritual to create chimeras - they can produce monstrosities by fusing animals together.
Note that by 'fuse', I do not mean any fancy genetic engineering. Rather, the mages are literally combining fully-grown animals with blood magic to produce horrific, multi-headed abominations. It is a brutal and cruel procedure.
As a result, all chimeras end up various degrees of insane. However, the chimeras created can be extremely large sizes and extremely ferocious. A sufficiently large chimera is nigh unstoppable and utterly ravenous.
Taming them is somewhat possible, but very, very difficult and not reliable. They have too many heads, each head fighting for control of the body, and thus they are very unpredictable.
Any animal can be combined in a chimera - but most typically the mages are creating the three-headed snake, goat, lion combination.
So - what is the best way to implement such monstrosities? How to put all of these chimeras to best use of the kingdom?
The obvious answer is as beasts of war, but the chimeras are not easily controlled and people are concerned about releasing giant monsters over the kingdom. There are plenty of enemies that they want to unleash the chimeras on, but there is no way for the army to control who gets mauled.
There's been some success with pitting the chimeras in fighting pits and gladiator rings, but the guy in charge believes that these monsters could do more.
Right now, only one kingdom has the ability to create chimeras.
Assume that the leader here is a sociopath with absolutely no regard for the lives of animals.
Edit: Chimeras in question become much bigger than the sum of their parts. The mages are creating mythical type chimeras, the sort of:
Chimera mass increases exponentially to the number of creature's fused, although it's typically limited to three or four heads.