Have You Tried The Doofenslurper? It's a new drink available at World Showcase named after the mad scientist in Phineas & Ferb. It's available in 3 flavors: 

• Frozen blue raspberry topped with passion fruit sorbet foam at Fife and Drum Tavern at American Adventure.
• Frozen lemonade topped with passion fruit sorbet foam at Promenade Refreshments.
• Frozen strawberry topped with passion fruit foam at Cool Post in the Output