Here's the answer: shares run on three feelings, and the strongest is recognition. "This is literally my cat" is among the most-typed DM captions on the internet, because the viewer isn't sharing your pet, they're sharing their own pet through yours. Delight, pure charm, comes second and has the lowest ceiling alone. Attachment, where the audience knows the character and shows up for episodes, is the third, and it's the one that converts viewers into followers.
The craft behind all three is the narration layer, because your actor improvises and your edit writes. The head-tilt means nothing until the on-screen text says "he heard the cheese drawer." The caption is the second act that finishes what the clip started. The cut is the punchline, the scheme, cut, the aftermath. And original audio, the sigh, the tippy-taps, your off-camera laugh, outperforms trending sounds for character accounts.
Five arcs carry almost everything: the scheme (want, plan, execution, magnificent failure), the origin (the rescue arc, used sparingly so it never becomes a lever), the ritual (one repeated behavior until the audience owns it too), the dynamic (the cat and dog's treaty negotiations, a sitcom that never runs out of episodes), and the verdict, where the animal tests a product and rules on it. That last one is the commercial hinge: an audience trained on honest verdicts believes the sponsored ones, and the animal voting with its body is evidence no human influencer can fake.
The full engine is Volume 4 of our Viral Pet Influencer Guide.
Episodes, not clips.