Heracross is a bipedal, beetle-like Pokémon covered in a blue exoskeleton. There is a long, pronged horn on its forehead. The horn ends in a cross on the male and a heart-shape in the female. On either side of the horn is a short antenna with a spherical tip. Heracross has oval, yellow eyes. Its forearms have a pair of spikes near the wrists, while its thighs have a single spike each. It has two claws on its hands, and a single long claw on each foot. There is a single pair of wings covered by is carapace, which can been seen during its release from a Poké Ball in the 3D games.
Mega Heracross is bulkier than its previous form. Thin orange markings now rim its head, hands, and shoulders. Additionally, there is a half-circle, orange marking over its eyes. It now has a long, pointed nose that curves slightly upward. Its back now lacks wings and is completely yellow. The horn on its head has grown into a large, simple spike with two smaller spikes on the front. The antennae have lengthened as well, and now have ovoid tips. Mega Heracross's forearms have thickened and lost their spines. This Pokémon has a high body temperature, so it opens the shell on its torso to allow heat to escape.
Heracross's claws allow it to dig into the ground for sturdy footing or climb trees. Using its horn, it throws opponents or competitors for food. It lives in forests, where it feeds on tree sap. As seen in the anime, Heracross has been known to compete with Pokémon such as Pinsir for food. The same episode also shows Heracross allowing Butterfree to feed on tree sap after Heracross has finished its meal. In addition, it is shown to suck sap from Grass-type Pokémon such as Bulbasaur.