I don't think G.I. Joe comics writer was a big fan of the character Serpentor--although, from that link, Hama may have suggested what his voice might be like. Serpentor was a clone, created with the DNA of some of history's greatest warriors; but Cobra may have forgotten some of those warriors were also the most ambitious men in history, and may not have been content to take orders from Cobra Commander...I believe Hama liked to keep one foot in the real world for the title, and Serpentor may have been a step too far. Which is a shame, since he's able to work wonders with him inside of five pages.
From 1987, G.I. Joe Yearbook #3, "My Dinner with Serpentor" Story by Larry Hama, pencils by Mike Zeck, inks by Dennis Janke. With the "Kitchen-Vipers" out with "Belgian Flu," cooking duties are being fielded by the Dreadnoks; which means dinner is chocolate donuts, grape soda, and microwave pizzas. The officious Dr. Mindbender is so shocked I'm surprised his monocle doesn't drop; but Serpentor is more than fine with it. In fact, it reminds him of a little story from 52 B.C. when the Roman army held siege the Gallic fortress of Alesia. Although he's not named here, Julius Caesar was the general, and worries the siege is taking too long and that his troops morale may start to slip. (I'm not sure how Cobra found his remains, but Caesar would certainly have been a candidate for use in creating Serpentor.) As a few of his troops eat their meager rations, a "signifier" demonstrates a little trick to make them more palatable:
Caesar has the trick spread around, but the tide nearly turns against him when the Gauls' relief army attacks the Romans' rear formation...and gets completely shut down. With the Gauls cut off, the Roman siege continues apace; and it's here that Dr. Mindbender calls no way.
Serpentor downplays it as "just a random memory," but now you know. I don't think Hama had the opportunity to do more of these, but I would've loved more five-page backups with Serpentor dropping the history. Most of it would probably be lies, but still.