A fire could be called Kestral

Fire: Scorpion

Lightning: Raiden

Poison: Reptile

Ice: Sub-Zero

Smaug

Spyro

Poison: Taco Bell, Venom, My ex

Lightning:Thor

If female poison, Medusa

Black colored fire: Alduin

Peril (wings of fire)

Torch (fire)

Voltage (lightning)

Butcher (blood)

Prism (crystal)

Avalanche (ice)

Viper (venom)