Saguarosaurus

Saguarosaurus is a hybrid of the Tyrannosaurus Rex and a Saguaro cactus. Saguarosaurus has the strength and speed of a powerful T-Rex, along with the spines and defensive capabilities of a cactus. Height is one of this dinosaur's main features since both of the organisms that create it are tall. Being part dinosaur and part cactus means that this dinosaur has the qualities of both creatures; loud or still, destructive or protective, terrifying or majestic. 

Dinosaurs and cacti can both be frightening, but combining the two would create a truly shocking situation.