Best movie monster?

[TheFrighter]

The Spiral Zone? (another great show, btw)

Probably but I don't see mutant plants in the intro.

_

[KyriakosCH]

There was at least one car which carried a green (plant-like) chain mace  I thought you meant that as a "mutant plant car".
Not easy to find an image, though. It's barely visible in the intro (but not really, since the car's top part where the mace is, remains off screen).