They're Made Out of Meat

A short story about two space explorers happening upon a new alien race. However, much to their disgust, they find that they're... meaty. Three guesses as to what this race is.

Written by Terry Bisson and nominated for a Nebula Award. Can be read here. Enjoy a short film adaptation of it here: low resolution (with credits and intro). high resolution version (no credits or intro)

This short story provides examples of:

An Aesop: Overlaps with Fantastic Aesop.
Easy Amnesia: The aliens are surprised that meat can think, even so they are able to "smooth out" the thinking part of the meat (the human brain), making the time they probed seem like a dream. Although if it doesn't work, their test subjects will be dismissed as crazy.
Energy Beings: The meaties are literally the only race that die as meat. One race starts as meat, but eventually "ascend".
Fantastic Racism: In the end, the explorers decide to strike the record of encountering the meaties and declare this sector empty, believing that first contact would be extremely awkward. As one of them puts it, "What are we going to say to them? 'Hey, meat, how's it going?'?"
Faster-Than-Light Travel: Meat cannot do that, because it's confined to C - space and therefore limited by the speed of light.
Meat Through an Explorer's Eyes
Insignificant Little Blue Planet: And just plain weird, to boot.
Invisible Aliens: they've done some abductions, but wiped the abductees' memory.
Squick: In-universe, to the explorers.
Starfish Aliens: Apparently, all known aliens are Energy Beings: there is one race that undergoes a "meat" stage, but ascends late in life, and another that is partially meat.
- The explorers certainly consider the meat this: meat communicate and entertain themselves by squirting air through their meat and flapping their meat at each other, which meat shouldn't be doing because it's meat.