The Autobots are lucky to have Longarm - in the Season 2 episode "Autoboot Camp," Megatron was talking to the double-agent he had stationed on Cybertron when Bumblebee and Bulkhead intercepted the transmission. It was heavily scrambled, but they got the gist of it. And since Longarm already had experience finding spies, 'bee reported the news to his old friend, trusting that the situation would soon be under control. Nothing more to worry about, right? Right?
Shockwave is the ultimate spy. Able to change his voice, energy signature, and even his appearance at will,
he has spent years infiltrating the Autobot power structure. Graduating near the top of the class from the Autobot Academy, he moved through the ranks of the Elite Guard, eventually becoming head of the Intelligence Division. Not once did anyone suspect the bright, friendly Autobot known as Longarm of being a devious enemy spy.
Unlike Sigma 6 Firefly, the reveal of "Longarm" as the traitor actually did catch people off-guard: even the smart fans were snowed. See, a game on Cartoon Network's site listed Ironhide as a Decepticon, so when he debuted in the same episode that centered around a traitor, the spoiler-happy fans assumed he was the one, and never looked any deeper. Ha ha ha! Misdirection. Was that intentional on Hasbro/CN's part, or just blind luck? Probably the later.
The change from Longarm to Shockwave is actually pretty substantial.
There's so much twisting, shuffling and otherwise repositioning of parts that by the time you're done, the only thing that's really the same is the chest, and even that looks different because it has a gold Decepticon symbol rather than a silver Autobot one. Shockwave is 8½" tall, so he towers over his previous form, his hands and feet are entirely different forms, and his limbs are longer. He still has treads on his shoulders, but new panels flip out to break that up.
But what really sets him apart is the head. The white face completely disappears, replaced by a blank black visage with a single round red eye in the center - a nod to G1. The white bars rotate up to become antennae, so he loses the scuba look, but starts to resemble Armada Megatron. The instruction booklet incorrectly displays the transformation of the head: they don't show the Longarm face disappearing, and neglect to mention that the neck pulls up out of the torso. Whoops. Anyway, make sure you don't forget - the neck goes a long way to changing the bot's look.
Longarm's crane detaches from the robot's back, and transforms into a cannon for Shockwave. He can hold it in either hand, but of course, a lot of fans are going to put it on his left, so he looks more "G1-y." There's a silver Decepticon symbol on the barrel, which is sadly visible on the underside of the crane in Autobot mode, which kind of ruins the illusion.
Even Shockwave's altmode is different from Longarm's, though not quite to the same extent as the robots. He changes into an "H-tank," which is... a tank that's shaped vaguely like an H. Again, this is a design parallel with Armada Megatron, but that may be unintentional. See, after Beast Machines ended, Hasbro started development on a new line known as "Transtech," but
it was eventually cancelled and they imported Japan's Car Robots cartoon and toyline. Some of the designs were reworked for Armada, but Animated Shockwave has some undeniable similarities to Transtech Megatron's concept art in both vehicle and robot modes. As long as you mentally simplify all the extraneous gew-gaws. So don't blame Shock for looking a bit like Megs: they have a common ancestor.
Anyway, the tank is 8½" long, and just over 2" tall.
The turret turns and the barrel can raise to aim at higher targets. And to help it look less like an unfolded crane arm, two more small guns flip forward to flank the main cannon. Still, let's be honest: it's pretty apparent this is the same vehicle as before.
Shockwave/Longarm is a really impressive Transformer. The engineering had a lot to accommodate, and actually does it very well; both robot modes look unique, and are playable in their own ways. True, the tank and crane are quite similar, but that's hard to avoid - besides, the 'bots are more important. Bottom line, this guy's a lot of fun, and the designers have done an excellent job.
-- 01/20/09
reporting to 
Longarm's crane mode is 6" front front to back, more than 4½" wide and at least 3" tall. The crane arm can raise nearly up to a full 5", and it rotates 360°, as well. Sadly, the arm doesn't extend, at all: it can retract a bit, but it's spring-loaded and pops right back out. The actual hook is on a swivel, and flops around freely.
you're done" Transformers, but there is a bit more going on, here. Once you change him into a robot, he stands 7¼" tall, thanks to the big treads on his shoulders. His forearms are a bit stumpy, because of the way his elbows work, but he's still very poseable and has a nice look. He's seems friendly and trustworthy, with metallic blue eyes on a white face, and a black panel on his forehead. The white bars running down the side of his head make him look like he's wearing a scuba mask, but it's still cool.
