Possible Clues:

• Ferocious dinosaur, familiarly
• Frightful dino
• Predator frequently appearing in Calvin's daydreams in "Calvin and Hobbes"
• Quintessentially scary dino
• “Jurassic World” beast, for short
• Dino with comically tiny arms
• 'Jurassic Park' predator
• Chicken ancestor
• "Jurassic Park" predator
• Tiny-armed dinosaur