theres a stump in central hyrule (remains of a giant tree) that you can find a fire greatsword on also next to the hyrule castle shrine same room has a fire greatsword Thunder weapons can be found more so at the coliseum with the lynel and beasties there.
It's not a tooth but Horn you should be needing. Go to Riola spring theres a cave towards the back set up a fire wait til dawn and BOOM he spawns right in front of you.
Locations of all three i've found.
Also if you have gerudo tower just behind it on the mountainside is a cave with a golden...