Toxix

Drogon, Rhaegal, Viserion, Balerion, Meraxes, Vhagar

Torch (fire)
Voltage (lightning)
Butcher (blood)
Prism (crystal)
Avalanche (ice)
Viper (venom)

(If fire) mirmulnir (first dragon fight)

Crosis the Purger

Fire: Scorpion
Lightning: Raiden
Poison: Reptile
Ice: Sub-Zero

Poison: Taco Bell, Venom, My ex

Smaug

Spyro

Ghidorah if lightning

(If fire) Bakugo