You see, the first Predator that come to Earth is a fugitive being hunted down by other Predators and he has a weapon that he wants to give the human race to help them in their fight. This weapon in called the "Predator Killer" and it's basically an Iron Man-style Predator suit of armor. I guess Iron Man 3 gave Shane Black a few ideas, unfortunately, that Predator armor looked goofy as hell.
When the suit makes its big debut at the end of the film, some asks what it is, and the main character McKenna says, "That's my new suit. Hope it comes in 42-long." Then it cuts to black and I roll my eyes.
Instead, McKenna, his son, Rory (Jacob Tremblay) and Casey Bracket (Olivia Munn) have all just survived the final attack of the Super Predator (referred to as "The Upgrade" in the script) when a helicopter lands. Out climbs...Dutch Schaeffer (Arnold Schwarzenegger), his "face haunted; etched by pain." Dutch tells the trio to come with him, and when Rory asks, "Uh...me, too?", the franchise's second-most iconic badass smiles and says "Especially you."
Seeing Dutch make his big return to the franchise would have been pretty cool. But, it still wouldn't have saved the film from it's story and script issues. Regardless, would you have liked to see this original ending over the ending we got with the toy-looking "Predator Killer" suit?