Slag is the name of a fictional character in the various Transformers universes.
Transformers: Generation 1
Slag (Scories in Quebec, Canada, Tricex in Italy) is very tough, strong and possesses impressive firepower. In dinosaur mode, Slag can spew from his mouth a bolt of 3,000 degrees Celsius flame up to 80 feet (25 m) 2 degrees to left. He possesses enormous strength and can shatter a brick building with a single blow from his armored head. His horns can also shoot high powered lasers. In robot mode he carries a high-energy laser rifle, anenergo sword and a rocket poom.
Slag's biggest weakness is his over-aggressive behavior, which can cause problems relating with other Autobots. He is also noticed for being the only Dinobot who would dare argue with the leader Grimlock over his commands (ironically, he is usually seen as the group's second in command). He joined the Autobots in the cartoon and comics in their first year (1984), but his toy wasn't released until 1985.
Slag was created by Wheeljack and Ratchet on Earth in 1984. He was created along with Grimlock and Sludge as the original three Dinobots. It has not been explained why he or the other Dinobots were able to be fitted with personalities, which can only be found on Cybertron from Vector Sigma. Apparently there is a difference between the brain and personality in Transformers. Their brains are simple, yet still it is the personalities that make them sentient. It is evident that the addition of personalities, or "sparks" and their origin was after the fact, and was hoped that this inconsistency would be overlooked.
When brought online, the Dinobots rampaged through the Ark, causing Optimus Prime to order that the they be rendered inert, but when he and the other Autobots were captured by Megatron, Slag and the other Dinobots were given cerebral upgrades and thus were able to rescue Optimus and the other Autobots. Shortly after, Megatron convinced the Dinobots that Optimus and the Autobots were their enemies and ordered the Dinobots to kidnap Optimus Prime. Wheeljack and Ratchet, with the help of Chip Chase, created Swoop and Snarl and the two new Dinobots were used to rescue Prime from Grimlock, Slag, and Sludge. During that battle, Optimus saved the original Dinobots' lives and they then realized that the Autobots were really their allies.
In 1985, an island with real dinosaurs was found by Powerglide and Bumblebee. Optimus decided that "Dinobot Island" would be a good place for the Dinobots to train and practice their fighting skills and avoid damage to the Ark. Moreover, they were also placed there so they could learn how to co-exist together as one group. Megatron and the Decepticons found out about the island and wanted to harvest it for all the energy it produced. The Dinobots were thrown into a tar pit, but they all survived and used real dinosaurs to help them attack Megatron.
Later, the Cybertronian Autobots and Decepticons began to malfunction because they ran out of Cybertronium, a crystalline substance only found on Cybertron. The Dinobots, having been created on Earth, were not affected and were sent to Cybertron to get some. Once there, they disappeared and Spike and Carly went to Cybertron to find them. They found Swoop, who led them to the other Dinobots that were captured and working for Shockwave. Eventually they were freed and brought the Cybertronium back so that the Autobots could be restored.
In The Transformers: The Movie, the Dinobots traveled in the shuttle with Optimus Prime towards the end of the attack on Autobot City and fought with Devastator. Slag was the Dinobot that knocked Devastator down. When Galvatron later attacked, they accompanied Kup and Hot Rod, but their shuttle was shot down on Quintessa and Kup and Hot Rod were captured by the Quintessons. On Quintessa, the Dinobots met Wheelie, led them to save the others Autobots. They took a ship to the planet of Junk and accompanied the Autobots when they attacked Unicron.
In the post-movie episode "Call of the Primitives", Slag briefly took on the leadership role of the Dinobots, when it was presumed that Grimlock was destroyed.