I have always enjoyed the odd optical illusion
and was excited to discover the Mighty Optical Illusions website.
I lifted this example to catch your eye. Click the image to enlarge.

Source: Mighty Optical Illusions

Like always, once I get to see improved, better version of a previously featured submission - it goes live immediately! It doesn’t matter how many times similar effect has already been showcased. And what we have here today is "seemingly animated" pattern on steroids! If I can recall correctly, last one I have enjoyed so much (belonging to the same category) was the Running Snakes promo. Check out the psychedelic formation below! Can you really believe the image is static, and that the motion is just an illusion? Try opening it in full-size to experience the effect in its full glory. From now on, this one is my favorite!

[...] Scoop: Mighty Optical Illusions (c) is a website dedicated to optical illusions, magic tricks and puzzles. And the best thing about them, they’re free! Yes, free free free pictures free images! Single sentence describes this website perfectly: "When the perception turns against you!". Providing regular updates, giving quick and easy aces to our database makes our guests coming back. We are growing fast and giving our best to keep the throne of Internet leading Optical Illusion website. ...