Wanna own real live dirt The Undertaker used to bury A.J. Styles at Wrestlemania 36???
Better act fast because the WWE has collected the soil and put it up for sale -- and we're told it's already in super-high demand!!
If ya missed it ... 55-year-old Undertaker beat Styles in an epic "Boneyard Match" at Mania back on April 4 -- which featured the two wrestling stars fighting it out in a cemetery.
Now, to commemorate the tilt, WWE is selling real dirt from the night .