The Spikle is a creature in the Keen 4 mod The Terror from Outer Space by Dr. Colossus. This is small native lifeform of the planet Phaelox and its asteroids.
The official help text states:
These little guys live near water or in burrows. Actually, they do not want to hurt Keen, but if you step on them it will be very painful..
The Terror from Outer Space