The most unsettling and the most biologically specific of all the creature watercolors — a work in which Sidney's imaginary zoology becomes genuinely alien. The composition is organized around a series of large diagonal black forms — dense, hairy, fusiform shapes that run in parallel from upper right to lower left across the yellow-white ground. These are not the transparent spheres or banded worms of Sea Creatures I; they are darker, more aggressive, more ambiguously threatening. The black is absolute — dense ink or very dark watercolor, the surface texture of each form suggesting fur or spines or the dense cilia of something that moves by undulation.
Between and around these dark forms, the named creatures operate: a yellow-orange slug at center with a small head and visible mouth parts; a pale lavender animal at center-left with horn-like protrusions; at lower left, a brownish fish-like form with a large open mouth; scattered throughout, smaller creatures in gray and teal with careful linear detail — antennae, spines, segmented bodies. Each is rendered with the care of a natural history illustrator who has never seen the creature but imagines it with complete confidence.
The dotted and spotted forms scattered through the composition add another register of biological variety: circular patterned creatures in black with red and green dots that read as either natural markings or bioluminescence. One creature at upper right — black, round, spiky — could be a sea urchin or could be from another planet.
The yellow ground, which in other works suggests warmth and light, here reads differently — as an acid medium, the color of formaldehyde or of something preserved. The dark creatures move through it as if it is the only world they know.