Martian Walker

Like everything else in Martian Madness it arrives with the invasion and appears nowhere else, so meeting one means a probe already got away from you. Only a single walker exists at any moment, which is the one mercy here: however badly the wave is going, you will never be handling two of these.

It covers ground quickly for something that size, stops once it has closed to a comfortable distance, and then hoses the area with laser fire. The shots have deliberate inaccuracy built into them, so there is no clean line to sidestep and no pattern to memorize. Constant sideways movement is what beats the spread, rather than timing individual shots. It also cannot fire while it is airborne, which comes up more than you would expect given how much it jumps around.

Damaging it resets its firing timer to something slightly longer than its normal interval. A weapon with a high enough rate of fire therefore locks it out of shooting entirely, and a walker that never gets to shoot is one of the safer things in the event to stand in front of.

Neither the walker nor its lasers pass through solid blocks, and it is tall enough that it cannot follow you into anything low. A wall of reasonable height shuts it out completely. That is why a prepared arena turns the enemy with the largest health pool in the whole event, saucers aside, into a non issue, while fighting one in the open is genuinely dangerous. It also needs a clear line to you before it will fire at all, so partial cover is worth nearly as much as a full wall.

• It is lifted straight out of The War of the Worlds, where the invaders walked around in tripods. The novel's machines carried heat rays, and while this one fires something else, a heat ray is a weapon you can end up holding yourself.
• There appears to be a brain riding on top of it, doing the steering.