Imagine you're a panda that's drank a little too much fermented fruit?
What: Bamboozled is one of my favorites, mostly because I stumbled upon it from this meme  and decided It must be a part of the Optical Toys collection. The perception here is that the tall bamboo sticks appear to be both angled and will move back and forth in the peripherals of your vision.
How To: You can change the sizes and amount to make the illusion stronger for you, as well as mess with the colors. Ultimately you’ll find that the outline colors that create the contrasting shapes will change the efficacy of the effects, though for me also a lot of smaller squares seem to work best.
Explain it: This is a type of illusory motion, where the part of your brain that perceives motion is getting tripped up by the black and white outlines… as per Wikipedia:
Apparent motion has been suggested to be caused by the difference in neural signals between black and white parts of an image. While white parts may produce an “on-off” signal, the black parts produce an “off-on” signal. This means for a black part and a white part presented simultaneously, the “on” part of the signal is separated in time, possibly resulting in the stimulation of motion detectors
I've researched these illusions in my spare time but am clearly not any kind of expert and my explainations are pretty smooth brained, if you find something mis-cited, earlier examples, or general mistakes please new let me know via firstname.lastname@example.org, be kind!