Complex sentence: On his way to buy groceries, Peter Griffin instead buys a "retarded" horse and enters the horse in a race, only for it to end up causing $100,000 worth of damage at the race track.
Split into simpler sentences: On his way to buy groceries, Peter Griffin instead buys a "retarded" horse and enters the horse in a race. The horse causes $100,000 worth of damage at the race track.