The Spiked Saucers appear in the machinery levels in Crash Bandicoot, the sewer levels and the firefly levels in Cortex Strikes Back.
They typically block Crash's path while he is navigating through each level and do not attack Crash directly, and act more like a roadblock in his path.
They usually appear in pairs of two or three.
They are small robotic ships that float in the air, with a row of spikes on the side. A small tentacle-like camera come out of the top of the robot.
Walking versions of this enemy were supposed to appear in Crash Twinsanity, as shown by concept arts, but were ultimately scrapped probably later in development, since a fully rendered and textured 3D model can be seen in said concept arts.
In Crash Bandicoot, this enemies move up and down or stand still, blocking the path. They cannot be defeated by any attack.
In Cortex Strikes Back, they can be seen in a full 3D environment and here they move around or stand still, acting very similarly to how they moved in the previous game. Also in this game, in the dark level, the Spiked Saucers appear to be able to light up the camera on top of them to illuminate their surroundings.