Idea I'm too tired to write properly:
Larryboy's driving through Bumblyburg on the trail of the Milkmoney Bandit (that one scallion mugger from the cold open of the Rumor Weed), whose been acting unusual lately. Not only is he doing more high-profile thefts than usual (he's got a very specific range, you know? it's in the name and everything), and not sticking to the shadows as well as normal, but he's been doing more thefts instead of fewer despite it almost being summer vacation (again, he's usually very particular about specifically taking milk money from school kids, so summer's his off-season). Larryboy managed to plant a tracker into the change the Bandit took in his most recent heist, and is following the signal to the warehouse district (it's a superhero city, gotta have a warehouse district).
He sneaks in, corners the Bandit with his usual theatrics... only to pause when he realizes that the Bandit looks really pale and wobbly. And then he glitches and says that his recent crimewave happened because "they" said they'd give him The Antidote if he did what they said. And when Larryboy questions this, one of Garyboy's plungers wraps him up and the virus comes out of the shadows.
As he's an eggplant of his word, he gives the Bandit a syringe containing the patch that'll purge the low-level malware in his system and tells him to skedaddle. Once the two are alone there's some hero-villain banter exchanged, they catch each-other up on what they've been doing lately (within reason. neither of them is about to reveal anything actually useful to one of their worst enemies), and eventually Larryboy manages to get loose.
The fight commences, during which it's revealed that Larry's suit has been reinforced to the point where Gary can't bite him through it. Larry's the more skilled fighter and Gary's stronger and has his Hydra powers, which makes them pretty evenly matched, at least until they've been fighting for a while and we're reminded that Code-Level entities don't get tired as fast as Character-Level entities (at east on average), so Gary gets the upper hand... metaphorically speaking.
Thankfully, he's not here to finish the job this time. Instead, he's here to show off a new trick he learned. He shoots a plunger (on a stick instead of a cord. that is something the super-suction ears can do even if it's only happened once in the Fib from Outer Space as a slapstick thing) at the Larrymobile, causing it to transform. Obviously it switches to Garyboy's color scheme, but it also gets a bit bigger and changes its signature smooth cucumber-shape into something more angular with segmented armor plating.
And, of course, once it's fully become the Garymobile Garryboy gains the ability to control it remotely. He takes it for a spin, knocking Larryboy around in the process, before portaling out. Communications come back online (because of course Garyboy was jamming his signal on top of everything else) and when Alfred asks if Larry's alright all he can think to say is that he needs a new car.
