This dragon named Grommel very clumsy, but extremely strong and very dangerous. Try to tame it in the same way as the Night Fury. Before you go down to him in the arena, take a bucket, which you will be able to fend off the dragon in the case of imminent danger to you. Warn attack the dragon in the game How to Train Your Dragon: The battle with Grommelem you can use the same bucket, which put him on the head with a minimum lunge toward you. For each step in the correct training you will receive bonus points.