Via Tinker comes this nifty little creative activity: Namelians. It's the kind of thing that you only need the slightest nudge to try out for yourself, I think, especially if you're in a whimsical mood. I tried it with 'Pacian' and came up with the following otherworldly little creature:
As you might expect, I've thought this through too much. This fellow is a filter feeder, drifting through an alien ocean, or perhaps even on the breezes of a denser atmosphere than Earth's. The curly hair-like bits sift for little morsels of food, while the creature hangs suspended from its large orange paddles. The smaller paddles provide stability and fine control. With its big compound eyes, it's able to spot predators coming from quite a way away, which is where the funnels and pointy bulge at the bottom come into play: it can suck water in through the funnels and shoot it out of its tail in a short burst to make a quick escape.
This one is called Bobby.