Complex sentence: After Mike leaves, Joshua is bitten by an escaped tarantula and accidentally knocks down the spider cages, causing him to be get killed by the spiders, after devouring him, the spiders grow to even bigger proportions.
Split into simpler sentences: After Mike leaves, Joshua is bitten by an escaped tarantula and accidentally knocks down the spider cages, causing him to be killed by the spiders. After devouring him, the spiders grow to even bigger proportions.