Realized it's Wednesday night and I forgot to do the Shellcreeper post.

These guys, named simply カメさん (kamesan) or "Mr. Turtle" in Japanese, are the original Mario Bros enemy after DK & Fire sprites. These turtles are pretty much the first thing the player encounters in Mario Bros, and would become the template for the Koopa Clan, Mario's main antagonists for the next thirty or so years.

As you can see in the video, not only are they the first enemy to appear, they are the first enemy demonstrated in the demo loops! It's fairly straightforward to defeat them. First, hit them from below, then kick them off screen when they're flipped. Failure to defeat it will cause it to exit its shell, flip it back over, and get back in it, changing blue, and moving at a faster pace than before.

Defeating a Shellcreeper causes a coin to spawn out of the pipes at the top of the stage.

The last Shallcreeper on a given stage will turn red and start moving at very high speeds.

Shellcreepers would return in Punch Ball Mario Bros, Mario Bros Special, Return of Mario Bros, Luigi Bros, NES Remix's Mario Bros challenges, and some of the Mario Bros remakes on the various GBA games.

They also appear on the Classic Court in Mario Power Tennis... well as in Super Smash Bros. Brawl on the Mario Bros. stage.

Their trophy description reads as follows: "Shelled enemies Mario and Luigi faced back when they were plumbers. They had to be bumped from below to flip them over and then kicked off the stage. The last one on a stage turned from green to red and raced really fast. If one got flipped but not sent off, it would eventually right itself and move at high speeds. They were simply called "turtles" in Japan."

Unfortunately, there's not a whole lot more to be said about these proto-Koopas.

These advanced troops paved the way for Bowser's eventual invasion, may history forever remember their brave sacrifice.