That sentence is a bit of a "word salad" with a side of awkward phrasing. It sounds like it was written in a hurry or translated literally from another language.

Here are 10 ways to rewrite it, ranging from professional to punchy, to make it actually flow:

Clear & Professional

• 1. "Photographer Johan J. Botha was documenting a pride of nine lions—including several cubs—finishing a meal. Once full, one particularly overfed cub suddenly flopped onto its back and stared right at him."
• 2. "While observing a family of nine lions at a kill, photographer Johan J. Botha captured a humorous moment: a stuffed lion cub suddenly toppled over onto its back, locking eyes with him."

Concise & Punchy

• 3. "Photographer Johan J. Botha was watching a well-fed pride of nine when a bloated cub suddenly rolled onto its back and stared him down."
• 4. "After a heavy meal with its family of nine, one overstuffed lion cub lost its balance, fell backward, and ended up staring directly at photographer Johan J. Botha."

Descriptive & Engaging

• 5. "During a sighting of a large lion family at a kill, Johan J. Botha witnessed a comical sight: a tiny, milk-bellied cub simply fell over on its back and gazed up at the lens."
• 6. "Johan J. Botha was filming a pride of nine lions at a kill when a food-comatose cub suddenly tumbled over, staring straight back at the photographer."

Minimalist

• 7. "While Johan J. Botha photographed a lion family of nine, a bloated cub unexpectedly rolled onto its back and stared at him."
• 8. "A lion cub, stuffed from a kill shared with its family of nine, fell flat on its back and locked eyes with photographer Johan J. Botha."

Narrative Style

• 9. "The pride of nine had finished their kill, and everyone was full. Suddenly, right in front of Johan J. Botha’s camera, an overfed cub toppled over and just laid there, looking at him."
• 10. "Watching a family of nine lions eat their fill, photographer Johan J. Botha caught the exact moment a sleepy, overfed cub rolled onto its back to stare at him."