Groganches reside in three locations within the BOTTLE SHIP. The first is a Swamp Zone in the Biosphere, the second is also in the Biosphere in Experiment Floor 3, and the third is in the Cryosphere's Experiment Floor outside the Materials Storehouse. There is also an observation deck in the Biosphere with two unusually large Groganches walking behind glass. Samus cannot reach them, but they can be killed once the Wave Beam is authorized; killing them offers no reward.
The Groganch's skin is very similar to that of tree bark, allowing the creature to easily blend in with forest environments. The creature has six spidery legs, an elongated head (resembling that of an ostrich or giraffe) mounted on a jointed neck, and an abdomen adorned with an orange bulb on one side. A Groganch's death will result in its orange eyes and bulb decaying to a dark green. Strangely, a close look on the bulb at this point reveals a translucent outer shell containing a smaller spherical structure inside. They are also one of the few enemies on the BOTTLE SHIP to leave behind a corpse rather than disintegrating (though it disappears upon leaving the room).
The Groganch's legs also have a 360-degree rotation radius, allowing it to merely rise up backwards as opposed to picking itself up. This results in two different stances of the Groganch: a shorter, more mobile form resembling a spider, and a taller, lumbering form resembling a sauropod.
During battle, the Groganch primarily attacks by firing globes containing noxious gasses from its bulb. Upon impact, the globes explode and release purple gas. Samus can either dodge or shoot the globes before they reach her. The Groganch may also strike at Samus with its head or legs. To defeat a Groganch, Samus must target its bulb; striking it with a Missile will momentarily stagger the beast.
After enough damage, a Groganch may change stances by flipping itself over. With its bulb on its stomach in its low stance, it moves faster and can perform a wild rush attack. With its bulb on its back in its high stance, its weak point is somewhat more protected and it can body slam underneath itself. However, its bulb is also susceptible to an Overblast in this form. In order to Overblast, Samus must first lure the Groganch into body slamming, lowering the bulb so that she can jump onto it. If Samus fails to fire, however, the Groganch will flip over again with her still on its back, slamming her into the ground to cause considerable damage.
- Samus in the Cryosphere Drifts
- "Sector 2 of the Bottle Ship was called the Cryosphere, and its sub-zero temperatures sustained many recognizable Zebesian life-forms. One was new to me - a massive creature with a spiderlike body that lobbed globes containing noxious gas. As I first encountered it in the Biosphere, it was obviously adapted to many environments."
"Groganches are terrifying creatures made from trees. The giant sphere at the center of its body is its weak spot and cannot be damaged elsewhere."
- The Groganch's battle theme is an abridged version of The Burning Lava Fish.
- In the Biosphere, a glitch will occasionally cause the Groganch to become stuck against a pipe bundle and walk endlessly without ever actually changing position. This makes the creature rather easy to defeat, as Samus can fire on the bulb while remaining out of range of its projectiles.
- The Groganch's bulb is similar to the weakpoint of the Dragotix. It also greatly resembles a Kashh Plant.
- The Groganch's dual plant-animal nature is shared by another Biosphere creature, the Gripper. Any relation between the two species is unlikely.
- The Groganch's head and ostrich-like qualities strongly resemble that of the Dachora.
- Concept art of the Groganch states that it lays eggs.