Complex sentence: Believing it to be Haley's Comet he goes to find it, coming across a large circus tent-like structure he is at first amused by the sight, but he and his dog Pooh Bear are quickly killed by mysterious clown-like creatures.
Split into simpler sentences: Believing it to be Haley's Comet he goes to find it, coming across a large circus tent-like structure. He is at first amused by the sight, but he and his dog Pooh Bear are quickly killed by mysterious clown-like creatures.