As Elmo peeked out the window, he noticed a familiar figure approaching. It was Oscar the Grouch, rolling his trash can along the sidewalk. "Oh no, Oscar's coming! Do you think he'll spoil the surprise?" Elmo whispered anxiously. "Don't worry, Elmo. Me have a plan," Cookie Monster said, a sly grin spreading across his face.

Cookie Monster stationed himself by the door, ready to distract Oscar the Grouch if needed. Meanwhile, Elmo and Abby Cadabby hid behind the counter, giggling quietly. "What's all this fuss about?" Oscar grumbled as he entered, his eyes narrowing at the festive decorations. "Me just baking cookies, Oscar. Want to try some?" Cookie Monster offered, holding out a tray of freshly baked treats.

Big Bird walked in, his eyes widening in surprise at the sight before him. Elmo, Cookie Monster, and Abby Cadabby leaped out from their hiding spots, shouting, "Surprise! Happy Birthday, Big Bird!" "Oh my goodness, this is amazing! Thank you, everyone," Big Bird exclaimed, his feathers ruffling with joy.

Elmo led the crowd in singing 'Happy Birthday' as Big Bird blew out the candles, his heart full of happiness and gratitude. Even Oscar the Grouch couldn't resist a small smile as he munched on a cookie. "This is the best birthday ever! Thank you, Elmo, Cookie Monster, Abby, and even you, Oscar," Big Bird said, his voice filled with warmth and appreciation. As the party continued, the friends of Sesame Street celebrated under the starlit sky, their laughter echoing through the night.