Megatron was currently flying to a destination while I resided in the cockpit. We had been flying for about an hour before Megatron spoke, breaking the silence. "So, you eat things and then grow, am I correct?" I tried to say yes, but it only came out in gurgles. Luckily, Megatron guessed correctly. "Good, and it seems that you are also rather smart! My army will distract the Autobots. While they are dealing with them, I need you to eat as many of the bodies as you can. Understand?"
I eagerly gurgled in agreement, knowing I was about to eat a lot, and I was already a bit hungry anyway—a win-win! Megatron noticed my cheery attitude. "Perfect, but try to stay hidden. I don't want them to know about you yet."
Time skip
It had been about two hours since takeoff, and I had a feeling we were getting close. "Remember the plan, and don't fail. We're here." With that, he transformed before suddenly hiding me behind his back.
"Optimus, been well? I see you brought your trusty watchdog. I was certain he'd be rusting in a scrapyard by now." I wondered who he was talking about when I heard a voice in the distance. "Why don't you invite him down here for a chat?" Then, a much more gravelly voice replied, "I know why you're here, Megatron."
"Hardly a surprise, Optimus. After all, we've been at this a long time, and your time has come to an end!" You hear him yell before tossing a purple crystal into the pit. When it hit the floor, everything started turning purple before Megatron shouted, "Rise, my army! Rise!" I watched as more eroded versions of the robots started rising from the ground.
"At last, symbiosis. I can feel it. I possess complete control over my army. DESTROY THEM!" Megatron commanded, and the undead began to attack the two Autobots. "Now, time for your part of the plan. Eat up. I can tell you're hungry." And I was, to be honest. My wish was granted as Megatron tossed me to the ground below.
I wasted no time and began eating the bodies the two Autobots had left behind, growing bigger and consuming the bots faster. Whenever I felt I was getting too big, I condensed myself to avoid being spotted, but I was still growing larger as the Autobots left me more bodies to devour.
After a while, the number of bodies started to decrease, which meant one of two things: either all the undead were being killed, so there were fewer bodies, or they were getting weaker. My thoughts were interrupted as a bunch of bodies piled onto me. Yep, definitely not getting weaker.
"You did well, Optimus, though this is just a prelude. You may want to save your strength for the main event," Megatron said confidently. Optimus retorted, "You will not succeed, Megatron, not as long as energon flows through my veins."
Megatron then jumped down in front of me, motioning for me to climb on. Seeing nowhere else to hide, I slithered underneath his armor, which I could tell caught him by surprise.
"Fitting, Optimus, for it is dark energon that flows through mine." He transformed and took off, while I slithered into the cockpit. Halfway through the flight, he broke the silence. "Word of advice—NEVER do that again."
"N̷̙̳̤͎̽̄͊̚o̷̧̪͕̓́͆ẗ̵̩̱́è̶͉̥̪͘ͅd̸̹̤̣̒͑̒."
There was another long moment of silence before Megatron spoke again. "It seems you're learning to talk, huh. How quaint."
...Oh my god, he's right.