The Monster Kits were molds to make a monster and either Living Ice or Monster Flesh to put into the mold.  The Monster Flesh was a lot like silly putty, and the Living Ice was a transparent rubbery substance.

Dissect-an-Alien was a plastic alien with a torso of clear, flexible plastic.  It came with twelve plastic “organs” and “alien blood”, which was really glow-in-the-dark slime.  The challenge was not in getting the parts out, it was in getting them to fit back inside the alien when you were finished.

The Monster Lab came with a water tank, two plastic skeletons, “Monster Flesh” and “Flesh Dissolving Compound”.  You would put the “flesh” onto the skeleton, fill the tank with water, dump in the dissolving compound, then put your newly-created creature into the tank and watch the flesh fall off his bones.