Complex sentence: When Shredder arrives, he is furious at them both stealing his helmet and hunting Karai and has Fishface shove Zeck into the first batch of mutagen within the mutagen vat.
Split into simpler sentences: When Shredder arrives, he is furious at them both stealing his helmet and hunting Karai. He has Fishface shove Zeck into the first batch of mutagen within the mutagen vat.