The blob was the result of a chemistry experiment in Sniffles' lab. It is made of acidic material capable of burning through various objects.
Sniffles decided to adopt it as his pet and took it on a walk. Meeting Lumpy, the blob humped his leg, until being dragged away by Sniffles. The two later drives around town and the blob sticks its head out the window. The slime on its body blew off and landed on The Mole's windshield, causing it to melt and kill the blind driver. The blob ends up melting through Sniffles' car and being carried off by the wind. It is last seen humping Lumpy's other leg, as the previous one had melted off.
Number of Kills
The blob is a purple viscous creature without a defined body shape and whose slime is apparently made out of acid chemicals, due to them being capable of burning through different kinds of surfaces, including skin. Its slime is the same color as its skin and its body has got a gelatinous texture. It also doesn't have any legs, so it crawls up to walk.
Judging by its appearance, it pretty resembles a larva of a possibly more advanced stage.