Permafrost (ice wyvern)

Fire: Scorpion

Lightning: Raiden

Poison: Reptile

Ice: Sub-Zero

Smaug

Spyro

Poison: Taco Bell, Venom, My ex

Drogon, Rhaegal, and Viserion (GameOfThrones)

44 (long live the wyvern king)

Poison: Venom, Pyro, Veneno.

Lightning:Thor

If female poison, Medusa