It stars Dwayne "The Rock" Johnson as some guy who really gets on well with wild animals -- especially gorillas. And then some corporation or rogue governmental agency drops some cannisters into his jungle, which releases mutagenic gas that transforms one of his favorite apes -- plus a wolf and a crocodile -- into a giant monster. Those monsters are then dropped in the middle of Chicago and we have one building-dropping motion picture!
You can watch the official trailer video here.