Which animal did people often ride and use for work?

The horse is the animal people rode and used for work before cars and trains existed. Horses could carry riders quickly over long distances, pull heavy carts and plows, and help with farming and construction, making them essential partners for transportation and labor for thousands of years of human history.

A goldfish and a butterfly can't carry riders or pull loads at all, they're far too small and not suited for any kind of work or transportation, unlike the horse's strength and size.

Horses were so central to work and travel that we still measure engine power in horsepower today, a unit invented specifically to compare early steam and combustion engines against the pulling power of a real horse.