From The Scientist's scientific notes:
SN-Tyr 616: The aim of the following sequence of experiments is to produce a small Tyranid creature with proficient tool handling capabilities.
The initial zygote is for what is referred to as a Termagant.
Additional genes have been added from another Tyranid species. Note: I find it amusing to steal a gene from something named a gene-stealer, Ha Ha.
The added gene sequences will lead the embryo to produce dextrous hands instead of the rather simple appendages that are usual for that species.
There will be no addition of any parasitic organisms to this creature, but I will add an electronic interface into the brain once it has fully formed.
Implanted training will be for the operation of control panels and mechanical duties such as; computer terminals, re-loading weapons, repairing mechanisms, and handling tools.
Additional training will be for increased intelligence, especially for mathematical skill.

SN-Tyr 667: Complete success. The Gunner Tyranid has passed all tests it was presented with and can operate the required equipment for the Predator tank. I have had to make it a "slave" in the system though, as it's rather insistent thinking often overwhelmed the Driver at times.

SN-Pred 002: Well, My goodness me. Ha Ha. The engines in this thing are hideously inefficient. No wonder they insist on cramming four of the useless things into each tank. This just won't do, no no. I shall replace them with two small power-units of my own design that will do a far better job of turning ordered fuel molecules into lots and lots of high-energy, smaller, molecules and well as lots of lovely heat and sound. This tank will epitomise the very nature of increasing entropy.

SN-Pred 342: Weapons test. The main gun installed in the turret works as expected, no surprises there. The Gatling gun, works amazingly well and can fire a minimum of 10000 rounds with no ill effects... well no ill effects to itself, there's plenty of ill effects to the targets, Ha Ha.

Then we come to the Electron cannon. How do I put this? Impressive just doesn't cover it... I shall attach the recording of the test as it speaks for itself quite well.
The video starts with a hand-held view of the ground which then pans up to reveal a Hormagaunt straining at a leash around it's neck. It has a muzzle on and all it's claws have been removed. A voice-over begins as the camera moves closer to the beast: "This hormagaunt has been bred to run, and run fast. You will notice that the hind legs are much thicker than those of the standard animal, and the forelimbs have been adapted to aid it's running. It has been implanted with the instincts and memories of a running dog."

A pale hand reaches out from behind the camera and strokes the beasts head, it clearly nuzzles the hand and appears as friendly as a family pet.
VO: "It has been trained to run this track as fast as is possible..."
The camera pans left to reveal a corridor of fencing stretching off into the distance out of a doorway and into a dry, dusty wasteland.
VO: "...and it has managed to reach speeds in excess of 85 miles an hour. But these experiments have come to an end. I have learnt all that is possible. So I have one final test..."
An Ork appears in view and attaches an electronic device to the gaunt's back.
VO: "This device measures both current and temperature and will hopefully yield some useful data."

The camera moves past the Ork that is now petting the gaunt and moves in to view a thick tube, covered in wires.
VO: "This is the test weapon, and will be better packaged for the tank, but it functions identically in every way to the final cannon..."
The camera reveals that the weapon is aimed directly down the corridor that the gaunt is clearly about to run down.
VO: "...This is the first test on a live being though and it will be interesting to see the results."
The camera is placed on top of the weapon and directed along the length of the corridor. The gaunt is visible in the foreground straining on the lead again, eager to run into the distance. The Ork has retired into the shadows and The Scientist now walks into view and approaches the gaunt. He bends down next to the beast and it appears to be in two minds as to continue to pull against the leash or to nuzzle the man.
The camera vibrates and the sound of an engine starting can be heard.
VO: "The vehicle's engines charge the capacitors and these are used to produce the electrons and power the magnetic lenses."

The Scientist reaches over and removes the collar from the gaunt and can be heard to shout "Go now, you are free!". The gaunt, needing no encouragement, bounds off into the corridor looking much like a greyhound. It is beyond the doorway and off into the wild in seconds. The camera's picture becomes slightly distorted for a short period and comes back into focus to show the gaunt disappearing into the distance, barely a dark speck heading towards the horizon. There is a bright flash, the entire picture becomes white and the loud clap much like thunder is too loud for the camera's microphone and the rest of the video is in silence. The picture slowly fades and shapes become visible again, the doorway, the fencing (which is now bowed outwards), and a bright while streak extending from the end of the cannon at the bottom of the screen into the distance where a fire appears to be burning.
VO: "The cannon performed perfectly, however, the recording device was partially vaporised along with the target and little data was recovered."