Gromaides (陰獣魔神像 ロヌイデス In-jū Majin-zō Ronuidesu?, lit. "Petrified Beast Devil Statue Gromaides") is a recurrent boss in the Contra series. It is a gargantuan alien beast featuring tentacle-like limbs, and is usually found guarding the entrance of an enemy's base.
Gromaides is a type of immobile emplacement located outside the second enemy base. It consists of a giant, dragon-like alien perched above the entrance which features two tentacle-like limbs with spikes at their ends, and from which it shoots rings of fire at the player. The limbs can be destroyed individually by shooting at the spikes in order to alleviate the whole ordeal.
The creature will also keep on spewing three rings of fire throughout the fight, although these have a determined trajectory and are not aimed directly at the player.
The mouth is its weak spot and becomes vulnerable every time it opens it in order to shoot. Once it has sustained enough damage, both its head and the door will explode, enabling the player to infiltrate the base.
This enemy appears as the boss of the River of Destruction. This time around, both of its arms have individual attacks; the left arm periodically shoots fireballs at the player, while the right arm unleashes a short, homing flame burst.
Once both arms are destroyed, the alien's head will begin to attack. It will keep on spewing large rings of projectiles which break into two smaller rings and home toward the player.
Its pulsating core is its weak spot, which becomes vulnerable once both arms are destroyed.
The waterfall guardian appearing in Contra 4 may not actually be Gromaides itself, but it is much stronger for sure. It has scythe arms and sharp tentacles at its base.
It is introduced when the player kills three Black Dirk McShooters at the top of the waterfall; it impales the fourth one and splits him in half, spewing green blood. "Gromaides" rises up, roars, and attacks by:
- Picking up the platform the player is on while firing energy projectiles out of its mouth.
- Having a tentacle try to stab the player from the side.
- Striking one of its scythed arms at the player, sending purple shockwaves.
Once the head has sustained enough damage, it slams the platform downward and starts the second phase.
The platform falls down and it starts charging downward at the player while shooting energy projectiles in a sweeping motion. When it has been shot enough, it spazzes out until it goes out of frame, presumably explodes, and the stage ends with its damaged head crashing down onto the ground.