Hit a Megonta's weak point - the stomach - and you can topple it over. It can't do anything until it gets back up, so you have a chance to strike.
Megonta is a fictional enemy in the Kid Icarus universe. Megonta appears as a common enemy found in Smash Run mode in Super Smash Brothers 3DS/Wii U. To defeat the Megonta, attack their weak point: their stomach.