Bryce Harper Rocks Insane Phillie Phanatic Cleats For MLB Opening Day

Bryce Harper's pheet looked phantastic on MLB's Opening Day Thursday ... 'cause the Philadelphia superstar rocked some custom Phanatic cleats for the occasion -- and they were INSANE!!

One of the spikes was covered in green fur, fake eyeballs and had the word "Phanatic" written across its side.

The other shoe had a little miniature Phanatic sewed into it ... with the mascot's baby feet popping out by Harper's toes!!!

The heat was created by custom shoe artist Soles By Sir ... who said of the spikes Wednesday, "Yes, we did a little something!"

Of course, Harper's no stranger to custom gear ... he's famously rocked Kobe Bryant tribute cleats in the past as well as some ultra-patriotic 4th of July footwear back in 2016.

As for the rest of Harper's Opening Day 'fit ... it was all just as on point as his cleats -- he showed up to the stadium in an Allen Iverson jacket that was clean as hell!!