I've seen it in a few sigs and brought up in some posts. My best guess, based on how it is used, is someone who buys a really fast bike and doesn't know how to drive it.
TMW Biker's Dictionary wrote:Squid - Acronym, SQUirrely kID. 1. In reference to younger MC riders with little respect to posted speed limit laws, self safety or safety of others. 2. Inexperienced newcomer, someone trying to ride beyond his skill level with arms flailing (like a squid) to try not to fall. This may be just a Southern term. 3. Stupidly Quick, Underdressed, Imminantly Dead. 4 Any SportBike Rider - seems this term got twisted along the way and has many meanings. 5 Sportbike riders who wear tennis shoes or flip flops, shorts, tshirts, etc. on their nice shiny new sport bikes. 6 Anyone that rides without all proper gear , rides recklessly, or rides beyond their limits.
The first time I ever heard of the term "squid" was from the nickelodean show called Rocket Power. I never actually thought anyone used it though until now.
Ah yes, I see it all makes since now. Squid this, squid that... I have been hearing it everywhere. A friend of mine, Anthony, just hit a wall. The guys at woork have been giving him a hard time about it. He is a squid. (he is ok, his bike is ok too.)