It has been said that exobiology is "the subject without subject-matter". Here, then, an attempt to remedy the lack.
(1) Reason would suggest that so splendid a species as the penguin must somewhere have their own planet. And yet, it is not so. For the Megapenguins of the galaxy of Arcturia are restricted to no single orb, but stride across the bridges of stars, ceaselessly, blasted by the stellar winds, circulating along the spiral arms. They are searching for something, and they think that they know what it is, but it cannot be put into words. And with this, dear people, we must rest content.
(2) One of the lesser-known species of our own planet is the snow bunnies. These come out in winter, and scamper rapidly across the tundra until they are happy and tired. But they have never been observed, because they blend in with the snow.
On the planet Lemuria, snow bunnies are the sole species. Like our own snow bunnies, they are white – because they like to be. Yet remarkably, snow on Lemuria is a pale, pale green. Hence on Lemuria the snow bunnies can actually be made out, flitting ghostlike across the frozen, phosphorescent wastes. This planet has no atmosphere, therefore there is no sound.
(3) A lovely planet to contemplate is Numlandia. It is larger than Jupiter, and proud of the fact. There are many curious species, but here the koala is king. Accordingly, too, the eucalpytus reigns supreme. Lacking all competition, it grows to a height of seven miles, penetrating the eternal cloud cover out into a skyful of stars.
When night falls on Numlandia, it covers the expanse of the planet, envelops the whole globe. At that time the koalas climb to the tops of their tree-homes, and snuggle, and whisper sleepy secrets among the leaves. Night on Numlandia lasts for a thousand years. Softly, deeply, they sleep.