Creative Writing: Opening Passage?

GuyAnswersGirls123

I've been trying to learn more about creative writing as well as reading more English fiction these days -- mostly commercial fiction but I've been trying to get my foot wet with literary fiction as well.

So one of the things I'm learning is that an opening passage to anything, ranging from a novel to a short story, needs to be captivating. And so I attempted this little passage this morning:

Snarf's ears perked up as the hulking figure kicked open the door and dropped a mud pile on the floor. "Zombies!" The humanoids shouted and grabbed their boom-booms.

Snarf scratched his ear with his foot and ran to sniff the new mud on the floor. It was poop, all right! Poop poop poop. It's like humanoid peanut butter. Snarf's tag wagged vigorously and he spun around and began to levitate.

What do you guys think about it? I'm down for brutal critiques including word choice, sentence structure, use of adjectives, adverbs, etc.

Updates
14 d
I meant to write "tail" instead of "tag" but somehow I kept re-reading "tag" as "tail" until I put it on GoG.
Updates
14 d
It's basically a story about a cyborg dog who actually isn't a cyborg, but that's a twist left for the ending -- even though there will be clues left behind everywhere that he isn't a cyborg despite his ability to levitate into the clouds when he spins when he's excited chasing his tail and his 24/7 wi-fi internet access.
Creative Writing: Opening Passage?
9 Opinion