Damp Squid
First of all, the word "squib," not "squid," is used in the phrase "damp squib." A species of cephalopod is the squid. Squid often live in a moist environment, but that is as close to this statement as they are going to get. Since I've already brought up squid, I should also mention another famous squid play on words: the old saying, "Hey, where's that sick squid you owe me?" We can now move on to "damp squib" after finishing our linguistic duty with squid.
Although many American audiences won't be familiar with this expression, a poll conducted in England revealed that the word "damp squid" is frequently misused in Britain. If you're not familiar with the word, damp squib, not squid, refers to something that is incredibly disappointing and falls short of expectations.
Once more, the issue is caused by the fact that the original saying makes use of a dated term that the majority of people do not use today. A squib is a little firework that makes a hissing sound while it burns before exploding mildly. You can understand why a damp squib would be perceived as unimpressive and unsatisfactory given that fireworks should be maintained dry for maximum effectiveness. Instead of ending with a bang, it would figuratively fizz out.