Robby (the Weirdo)

Robby is the main antagonist of the fourth Goosebumps SlappyWorld book, Please Do Not Feed the Weirdo.

History
Jordan Keppler and his sister, Karla, are spending the day in Carnival World with their parents. A few minutes later, the children find a brown-haired boy locked in a cage, in a secret part of Carnival World. There's a sign near the cage that reads "PLEASE DO NOT FEED THE WEIRDO." The boy states that his name is Robby Ferber, and that he is the son of Manny Ferber. He then begs for a bite of Robby's chocolate bar, and complains about his father, saying that he leaves Robby in the cage for all day, without giving him any food or water. Jordan reluctantly gives him some of his candy. Robby starts eating the chocolate, calmly at first, but soon begins to eat it furiously. Suddenly, he opens his mouth wide and violently vomits a huge glob of orange slime, that splashes loudly in front of Jordan and Karla.

To the children's shock, Robby soon turns himself into a giant, green-furred beast. He breaks the metal bars of the cage and escapes the park, destroying everything in his way. Since he is a shapeshifter, he can transform himself into anyone. Everyone starts running when they see the monster, and the park soon becomes almost empty.

This is followed by several encounters with Robby, all resulting in him getting away. Jordan then figures out how exactly they will capture the monster. His plan is, the next day there will be a picnic at Carnival World, for Jordan's class, with lots of food. Robby won't resist all that food and will surely show up in the picnic. When he appears, Manny Ferber, who will be hidden behind some bushes, will throw a strong net over Robby.

The next day, Jordan and his classmates were at the picnic, and Jordan was worrying because Robby was taking too long to appear. Jordan's teacher later ends the picnic and decide to go try some rides, starting with the Tunnel of Fear, where Jordan finds Robby. Robby turned himself into a perfect copy of Jordan, and pretends that he is the actual Jordan, causing Mr. Ferber to throw a net over the genuine Jordan, instead of Robby. Mr. Ferber puts Jordan in a cage and leaves him there, thinking that he was actually Robby. The book ends with Jordan stuck in the cage, begging for some food to the people that pass by.

Appearance
Robby's monster form is described as looking like a giant bear with green fur and giant green paws. The book's cover depicts Robby as having yellow eyes. Robby can change his appearance to make him look like anyone. He looks like a normal brown-haired boy in his "Robby" form.

Personality
Robby is always begging for food, and will turn into a vomit-spewing monster if he is fed. He shyly smiles whenever he asks for food in his "Robby" form. Robby is also a trickster, who is willing to lie in any way possible just to get a bite.