Baby Sheegoth

Baby Sheegoths are the young of the Sheegoth species. They have two legs, no visible eyes, no arms, and are protected by a thick shell of ice on their backs; this is grown to protect the flesh that, when fully matured, develops into a ridge of energy-absorbing crystal. They have huge, gaping mouths with incredibly sharp teeth. Baby Sheegoth are powerful hunters and can fire bursts of ultra-cold gas at prey, as well as ram their prey. The adult Sheegoths reign supreme in the Phendrana Drifts.

Samus encounters Baby Sheegoths in Phendrana Drifts on Tallon IV. They can be found in various rooms as well as in the open. They will attack Samus on sight if disturbed, making them a constant threat.

Similarities to Grenchlers
The Sheegoth of Tallon IV and the Grenchlers of Aether are often noted for their striking similarities: for instance, both are vulnerable only on the shells on their backs. The Luminoth and the Chozo, the dominant species of Tallon IV and Aether, had close ties in the past, and it is possible that either Sheegoth, Grenchlers, or some more ancient ancestor of the two species could have been brought from one planet to the other.

The developers of the games, Retro Studios, have no official position on this matter. As such, it is entirely possible that these incredible similarities are simply a coincidence.

Behavior
Baby Sheegoths inhabit the Phendrana Drifts, where they are most often found dormant with their heads buried under the snow. When Samus draws near, they will instantly awaken and attack.

Baby Sheegoths attack primarily using their breath attack: a projectile sphere of cold energy. However, the most unique feature of these creatures is their dorsal shells. A hard, smooth shell covers their backs, their only vulnerable area. This shell is extremely durable, but once it is destroyed, the Baby Sheegoth's bare flesh is exposed, and a few shots to that tender area are sufficient to end them.

A charged Plasma Beam shot will instantly incinerate them regardless of whether the back is exposed or not. Doing so will make them create an odd screaming noise before they die.

Metroid Prime Logbook entry
''"Morphology: Baby Sheegoth Glacial predator. Ice shell protects vulnerable dorsal area.

Metroid Prime: "Young Sheegoths grow a resilient shell of ice on their backs which serves to protect a layer of vulnerable flesh. With this being their only weak point, Baby Sheegoths will turn quickly in order to not allow predators the opportunity to strike at their backs. Powerful hunters, they fire bursts of ultracold gas at potential prey, then feast on their frozen victim."

Official website
"Young Sheegoths grow a resilient shell of ice on their backs, which serves to protect a layer of vulnerable flesh that eventually becomes a ridge of energy-absorbing crystal. Powerful hunters, they fire bursts of ultra-cold gas at potential prey, then feast on their frozen victims.

Two strong legs support the Baby Sheegoth's body, which is armless and protected by a thick ice shell. The head is dominated by a gaping maw filled with rows of sharp teeth."''

Trivia

 * The body of the Baby Sheegoth somewhat resembles the head of the creature in the Alien movies, from which the Metroid Series took some inspiration. Incidentally, they also bear some resemblance to the "Xenomorphs" of the same series.
 * If a Baby Sheegoth happens to fall into water, it dies immediately.
 * Upon dying, it can release a small amount of its freezing breath which is easily avoidable.