Often shortened to "R E F T" by inter-F R I D G Eal english speakers, R E F T E R S F is a simple green blob of goo the size of a few Megaverses... and the Blueprint Particles are W H A Ts. Aside from that small factoid, entities from larger realms often come to feast on this goo. They never make a dent due to the sheer size, and the W H A Ts are unharmed due to their small size (comparitively).
The goo contains clusters of T H E W H A T, and they move apart of each other. Part of R E F T's composition is made from melted W H A T s. The green goo is also good building material, which is why it serves as the walls of the R E S T A U R A N Ts.
This goo tastes 3x as good as a Great Borger, do not ask how this was discovered.