Sandalphon

In its unhatched state the Angel floats within a dark, egg-shaped cocoon, its silhouette loosely suggesting a human embryo. Hatching begins with distorted cries like those of an infant, after which it reshapes its own mass behind a visual blur, the same effect the series usually reserves for A.T. Field activity.

The mature body is flat and finned, closest in shape to a flatfish, though the resemblance is partly a trick: the paired markings on top are false, while the working eyes sit on stalks and the true mouth opens on the underside of the head, an arrangement compared to the ancient predator Anomalocaris. The creature shrugs off volcanic heat even with its mouth agape, yet its newly hatched form is aquatic and frail, and nothing confirms whether it carries a developed core or can raise an A.T. Field at all.

Whether Sandalphon is hostile at all remains an open question. Its pre-hatch vocalizations sound like a baby's, so its conduct can be read as that of a newborn rather than a combatant. Even its severing of Unit-02's cabling is ambiguous: a deliberate last strike, or the flailing of an infant mind, the series never says.

Designated the Angel of Embryos, with a name rendered as The Brother, Sandalphon debuts in Episode 10 between Israfel and Matarael. NERV attempts to claim the specimen while it sleeps: Asuka, sealed in a plug suit modified against extreme heat, descends into the volcano with Unit-02 to haul it out. The Angel stirs during the final phase of the extraction and battle erupts in the magma.

Its heat-hardened, pressure-proof body finally yields to a Progressive Knife that Shinji drops down to Asuka, the blade flooded with coolant to survive the environment. Its roar is recycled from Twin Tail, a kaiju from the Ultraman series.