Make Your Own Concrete Thwomp
Like most Mario video game characters, Thwomps are bad guys, yet are still somehow cute. These spiked cinder blocks have personality. Sure, they are trying to pulverize you, but you still have to love them.
If you want a nice solid concrete version, (because what else would you make a Thwomp out of?) Instructables user mactothefuture can show you how. He made this replica of the Thwomp from Super Mario Bros. and it looks awesome.
He used a mold box and cast the block from concrete. Now it is ready to smash anything the goes under it. Working with concrete is tricky, but I bet you can do it with some practice. All of the details are up on Instructables if you want to give it a try.
[via Nerd Approved]