Through 2/27, head over to GroopDealz where you can score this Ultimate Space Slime for only $3.99, regularly $15.99! That’s 75% off, nice! These tubs of Mars mud contain stretchable, slimy, sludge that glows in the dark. Turn down the house lights to achieve the maximum effect. Shipping adds $2.99 for the first item and $0.99 for each additional. Grab the deal here!