奇妙なモンスター達がいる絵本の中の世界。クリアしたページにはページの上側に結果に応じた★マークが表示される
Sesame Street: Once Upon a Monster (C)2011 Warner Bros. Entertainment Inc. Developed by Double Fine Productions, Inc. "Sesame Street(R)" and all associated characters and elements (C)2011 Sesame Workshop. Portions of "Once Upon a Monster" TM & (C)2011 Double Fine Productions, Inc. All other trademarks and copyrights are the property of their respective owners. All rights reserved.
WB GAMES LOGO, WB SHIELD: TM & (C)Warner Bros. Entertainment Inc