Here's an Illustrious model of "Arceus" from pokémon.

The classic & Shiny one are okay, but the beta form is not on point. (For the beta form I recommand to mix it with this model from mystery117)

Trigger word :

G0D-Pkmn, Arceus, pokemon (creature), horns, green sclera, red eyes, tail, grey skin, white fur, 

You can add for more accuracy : golden spiked ring around body, golden hoof, four-legged animal

For Feral : Feral

For Humanoid/Anthro version : Anthro (Or also Centaur or "taur" for a centauric anthro)

For Girl (humanoid) version : Rule63 (You can also use Futa for futa version)

For Normal Shiny Form : Shiny form, yellow fur

For the Beta form : Beta-Arceus, pokemon (creature), orange eyes, Yellow ocher skin

If you don't know what to remove for correct use. Just look at the tags of the pic from the model.