Jack O'Lantern (or just Jack) is a character from the episode The Mixed-Up Seasons. He is voiced by Jose Zelaya and Joaquin Mas.
Story
Jack O'Lantern belongs in the season of fall. After putting Little Flower back in the purple flower patch in spring, a voice went "¡Ayúdenme!". Dora, Boots, and the flowers go "Uh-oh!". Someone else was lost, which happens to be him. The pumpkin's name was Jack O'Lantern and said that he's lost and he doesn't belong where it's spring, winter, or summer.
Jack O'Lantern belongs with the other pumpkins in autumn. Dora & Boots had to figure out how to carry Jack O'Lantern home. Boots couldn't pick him up because he was big and heavy. So Dora & Boots use a wheelbarrow to carry Jack O'Lantern Boots rolls the wheelbarrow up to Jack O'Lantern. They were about to pick him up when they heard Swiper. Dora, Boots, and Jack stop Swiper by saying "Swiper, no swiping!" to prevent him from swiping the wheelbarrow. After that, Dora & Boots lifted Jack O'Lantern onto the wheelbarrow. He was heavy but they both lifted him together. As Dora & Boots push the wheelbarrow down the path, the wheelbarrow gets stuck in the mud. The viewer helps Dora and Boots push the wheelbarrow out of the mud. And then in no time, Dora & Boots are in fall. Now they had to find Jack O'Lantern's pumpkin patch but it was dark in the forest and they needed a light. Sure enough, Jack O'Lantern lit up the entire forest and was home.