In the beginning, Hasbro tried to pretend that GI Joe: Sigma 6 was a continuation of the storyline begun in SpyTroops and Valor vs. Venom, and, by extension, that these were the same characters. A scene added later revealed that these were new Joe members 20 years in the future, and that they'd merely inherited the codenames of their predecessors. Uh, what?
Tunnel Rat is an expert at outdoor survival tactics and can provide any small, portable equipment needed at any given
moment from his seemingly bottomless Sledpack. He is highly skilled at infiltrating extremely narrow areas, and uses his Sledpack in these small passageways as a fast, highly maneuverable land sled. His expertise helped the Sigma 6 team successfully infiltrate a previously impenetrable Cobra facility. The only access was an abandonned pipeline considered too small for concern. He glided through the pipe on his mobilized Sledpack, pulled an array of weapons from a hidden compartment in his pack, and captured the surprised guards before they even had time to reach for their weapons.
So, since this isn't Nicky Lee, from Brooklyn, he's a complete cipher. Who just happens to share all the old Tunnel Rat's skills and personality quirks. Of course, Christian Slater is just a younger version of Jack Nicholson, so it's not like these things only happen in fictional worlds. Maybe "F. Rutherford Chong" (yeah, I just made up a name for him) idolized the original Tunnel Rat and patterned his interests after him.
If Heavy Duty represents the zenith of the Sigma 6 format, then Tunnel Rat is its nadir. And naturally, we're talking size here,
not quality: Tunnel Rat is little, is what we're saying. He stands only 7¾" tall, and his limbs are very skinny. He's wearing the team's standard Sigma suit, which has ribbed panels down the side of the ribs and on the inner leg that are detailed with a fine diamond texture. He's wearing thick brown boots that look entirely out of place with his skin-tight spandex. They've got a heavy look to begin with, then there are strips of metal armor around the ankle and the top of the boot. Super bulky!
Tunnel Rat's suit is appropriately dark for a guy sneaking through pipes: it's mainly black with a few brown highlights. In the comics and cartoon, his hair was long and shaggy, and almost looked red; the toy tones it down, with just a little bit of brown hair sticking out from beneath his black watch cap (it's sculpted on, not removable - but you can take off his goggles).
Despite being the smallest figure in the line, Tunnel Rat moves just like the rest of them: hinged ankles and torso, swivel boots and waist, balljointed neck and swivel/hinge knees, hips, wrists, elbows and shoulders.
There's also a hinged communicator on his left arm, which they all had.
Tunnel Rat was part of the first series of "Soldier" figures, which means he was sold on a blister card rather than coming with one of those big footlockers. It's okay, he still gets a nice assortment of accessories, including two grenades, a submachine gun, a pistol with a laser sight and a removable clip (that even has a sculpted/painted bullet on the top) and a working butterfly knife. The pistol and grenades can plug into the removable webgear, or any of the various ports scattered around the surface of the Sigma suit - arms, legs, chest and back.
Finally, he comes with the "Sledpack"
mentioned so often on the filecard. It looks like a high-tech version of an auto mechanic's creeper, and like that device it's meant to be used with the figure laying on his back. There are two curved lights coming out the front, and the body of the sled can be extended by a few inches so more of the rider is supported. The sled can plug into his back securely, so he never has to leave it behind.
Tunnel Rat isn't the most impressive Sigma 6 figure ever released, but he's definitely unique. The accessories are decent, and as far as a reinterpretation of the character goes, he's not bad.