Be careful what you wish for...

[Hookbill the Goomba]

I wish that Fingolfin killed Morgoth.

Your wish is granted. However, Morgoth fell on top of Fingolfin and killed him. What's more, Sauron was the only one who saw the fight and so he took on the shape of Morgoth and became the new Dark Lord. He hid the body and took the Silmarills and ruled the armies much better than Morgoth ever did. Beleriand is in dire peril!

I wish Mount fang had wheels and could race Mount Zoom!