Complex sentence: Along the way the monsters almost kill Kermit's dog and finally engulf Andy and Evan until they all swarm off and huddle into one big pulsating ball-the monsters had become so vile and evil that they've started to attack each other.
Split into simpler sentences: Along the way the monsters almost kill Kermit's dog and finally engulf Andy and Evan until they all swarm off and huddle into one big pulsating ball. The monsters are so vile and evil that they've started to attack each other.