Complex sentence: As Foghorn is setting up the trap, he sees the dog setting up the same trap to use against him, only both of them realize that Daffy has been playing them against each other (and enriching himself in the process).
Split into simpler sentences: As Foghorn is setting up the trap, he sees the dog setting up the same trap to use against him. Both of them realize that Daffy has been playing them against each other (and enriching himself in the process).