Curly straw
From Transformers Wiki
The Transformers' Great War is a conflict that has spanned countless millennia, taken countless lives, and forever changed countless worlds. It has seen empires rise and fall, planets die and be reborn, and Cybertronians molded into the greatest of heroes and the most terrible of villains. Its beginnings lie in variety of factors, not least the state of Cybertron’s society, but ultimately, the responsibility for this most deadly of wars can be laid at the feet of a simple object: the curly straw.
Fiction
2005 IDW continuity
In 4th Cycle 499, a group of time-traveling Autobots from four million years in the future visited Maccadam's New Oil House in Rodion. One of their number, Tailgate, asked for a curly straw with his drink, and thus set in motion a chain of events that would plunge Cybertron into eternal war. When fellow time-traveler Rung lent over the bar to retrieve a curly straw, he knocked over a drink belonging to a Senate cadet. Stet The angry cadet promptly threw Rung into a window, triggering a bar fight that would see Megatron of Tarn, a bystanding miner with ideas about peaceful societal change, arrested. At Rodion's police headquarters, Megatron was brutally beaten by dirty cop Whirl, teaching the miner the power of violence, and setting him on a path that would eventually see him raise an army of Decepticons and overthrow the government, starting the Great War. Chaos Theory Part 1
Despite their terrible significance, Cybertronians continued to use curly straws well into the future. In particular, they were available at Swerve's, where Chromedome Life After the Big Bang and Aquafend made use of them. The Road Not Taken No galaxy-shaking repercussions to these incidents have been noted... yet.
Ask Vector Prime
Vector Prime was not fond of flimsy curly straws as construction materials. Ask Vector Prime, 13/5/2015