This week's animal idiom is...
Like a Fish out of Water
As in past weeks, I'd encourage you to write about the meaning of the idiom, and not to write about a literal fish out of water. While that's certainly permissible, you should be aware that many, many other entrants will be writing about fish, and you don't want to exhaust the judges with still another fish story.
This idiom means...
in a situation where one feels out of one's element or comfort zone, unsure how to act, different from the people around one.
Again, if you write using the meaning of the idiom, you're far more likely to come up with something unique, because there are any number of situations where one might feel uncomfortable or unsure. And you don't have to use actual gasping fish anywhere in your entry.
Yes, you may do so. But if you do, be sure to make it very special, lest it get lost among all the other fishy entries.