Grills inhaled deeply. He floated Sugar down to the ground. Then he charged at the rock at full gallop. At the last moment, before ramming into the boulder, he spun and kicked it.

And the reaction of his action was dramatic. He flew backwards. "Whooooa!!"

Anypony who looked at the boulder and not the airborn unicorn would notice it shrunk it size as Grills moved away from it.