The Hero Catapult is the exact counterpart of the Catapult.
The Hero Catapult, like the Catapult, cannot attack, but instead just has a special. If you let it get too close to your crypt, it will continuously use a special against your crypt, doing high damage and rendering it invincible. In these cases, you are nearly guarenteed to lose. The easiest way to beat the hero catapult is to attack it before it comes anywhere near your crypt.