Robert Swindells 
Hydra 

It was sick and hungry and a long, long way from home…
Something is causing mysterious circles to appear in the cornfields of Cansfield Farm. And someone, or something, has obviously terrified Barry Cansfield, the farmer”s bullying son. But when friends Ben and Midge sneak out to the farm to investigate, they discover a secret more terrifying than they could possible have imagined – a truly monstrous horror that simply must be stopped…