Terrible eyes and terrible claws

We have a good foundation of what the alien is; now all that’s left is to colour in the finishing touches. We do this by highlighting further details such as strange attire, eyes, or limbs. Let's see how Said has filled out the Alien in Phoenix:

He was dressed in a strange coat that looked like it was made of liquid metal, billowing behind him like wings. His flaming eyes were covered by mirrorshades, but Lucky could see cloven hooves protruding from the bottom of his coat: massive black hooves that could crush a Human head.

Said is embellishing what features are, well, alien, about the creature. A coat of liquid metal, flaming eyes, hooves that could crush a skull - these are all things that are starkly different to a regular human.

Skin, mouth, fangs, hands, skin, eyes, tail, nose, hat, shoes, antennae, tongue, ears, feet, wings, hair, legs, arms, voice, belongings

How do the examples show us just how alien and different the other creatures are from the protagonist?

Its long tentacles writhed, hook-like barbs on the tip of each one obviously designed to catch its prey. The creature roared again, louder this time, spit escaping from its mouth and spraying over the soldiers in its path. Biff could see the soldiers writhe on its impact, as if the creature’s spit was poison, or acid.

The saffak was armoured with thick black shell, all bumpy and ridged, shining glossy in the burning sun. The gloss came from sweat that streamed out of tiny holes in the shell, and as the sweat dried it turned to sulfur, leaving streaks of yellow powder and the smell of rotten eggs.

They had lights coming from their heads. Whether this was artificially generated or a natural feature of humans, Jola didn’t know. Their feet were long and webbed like amphibs, but this looked constructed, as they seemed to be made of the same substance as the black skin they wore. They each tapped on arm bands that lit up on contact. Did they have nav devices too, she wondered? But Jola’s thoughts were quickly dispelled when the spears the humans carried began to shoot from their hands.

Finish off the description of your alien by highlighting its strange or different features here.