Trailer of the movie

One day,  a solo scientist discovered a cave full of mysterious creatures he had never seen before, and he brought one of the creatures into his lab for testing. He finds the results intriguing and decides to continue catching and experimenting on the monsters.  The monsters are angry that their friends are being taken away, so they develop a plan to get them back.  The monsters came to an agreement under the rule of their leader : The Serpent King. Their agreement was that for every monster taken away from the woods, a human child would be taken from the park.  All of the monsters including Leafy praised The Serpent King and trusted that his plan would bring their friends back.  Each monster had to contribute to the plan, and Leafy's job was to lure the kids in with his cuteness and bring them to the Serpent King.  The people of the town had no idea why their children were disappearing, but in reality this was the only way the monsters could communicate with them.  The people of the town don't know about the solo scientist, so they have no way of protecting their children from being taken away.  How will they resolve this issue?

Leafy