One day, little Otyugh got hungry. "Wow, what fibrous creatures those look to be," he thought to himself, gazing at the critters in the neighbour's fields. "I think I'll have me a snack."
And snack, he did. So much so, that when the inevitable happened, he knew it would be epic (Nova). Locking himself in his private privy (Bone Wall [door], Sanctuary), he felt safe and ready for a good cleansing - some of those yummy critters had poisonous bits! (Purify, Quintessence.)
Patiently (SoP) he waited, perusing his favourite magazines (

HG), but to no avail - just a noxious semi-release (UG). As his friends hurried to see what was on the other side of the pasture fences (Oty, Epinephrine), little Otyugh had scary visions of what was to come (Nightmare).
When his accumulated efforts finally bore fruit (Explosion), everyone was stunned (Silence). The air pressure, mixed with the toxic fumes, knocked down nearby buildings (EQ), and hit the nostrils like a hammer (Gavel).
Everybody was overcome. Everyone, that is, but little Otyugh. He felt just peachy (Improved Heal).
THE END.