- "My real name is William Rendfeld. I was a twelve-year-old fan-fiction writer for a popular television show called Beast Wars, which featured all of you. That is, until New Years Eve, 1998. That night, while watching the ball drop in Times Square, I was kidnapped by aliens, thew same ones who seeded this planet with energon and created the flying island, the bungalow, and the Planet-Buster weapon. They turned me into this, and sent me here to stop Terrorclaw, and warn you about the future." 
Echowarrior is really fanfiction writer William Rendfeld. Kidnapped by aliens from his Indianapolis home and placed into the Beast Wars, Echowarrior is a dolphin/bat Fuzor with the head of a twelve-year-old boy. He carries the Dorsal Excalibur, a weapon which has extinguished the Spark of Antagony herself. He has died and been reborn twice, received the Matrix, been castrated, married, had a crush on an anime character, and fought terrorists.
Echowarrior's brother Phil was also brought into the Beast Wars as Ramblast, but not before Predacon Megatron hunted down and killed their parents. Thankfully, his Beast Wars collection was unscathed.
He's from the future and knows a lot about history.
During an alternate version of the Beast Wars episode "Coming of the Fuzors" in which the Fuzor Terrorclaw is introduced into the ranks of the Predacons, Echowarrior arrived suddenly via a Transwarp portal to save the lives of the nearly-beaten Maximals. Echowarrior quickly dispatched Sky Shadow, Quickstrike, and Inferno, as the Maximals watched him in awe. As Optimus Primal regrouped the Maximals to aid him, Megatron commanded his remaining troops to retreat.
Back at the Axalon, Echowarrior explained his mission and his origin. The aliens who sent Echowarrior to prehistoric Earth also gave him a map showing where all the crashed stasis pods were located across the globe. That, along with his extensive knowledge of Beast Wars events soon to come, such as Primal's evolution into Optimal Optimus and Megatron's attempted grab for the Ark, quickly tipped the war in favor of the Maximals. 
Twelve weeks later, Optimus Primal sent Echowarrior and Rattrap to the Alaskan Peninsula as part of Operation: America, and so Rattrap could learn about Christmas. After locating the stasis pod which had landed there, Echowarrior and Rattrap were attacked by Scavenger, Inferno, and Terrorclaw. Echowarrior temporarily stopped them with a little thing called, missiles. Ultimately, the stasis pod unleashed a new Maximal, Polar Claw, who frightened the three Predacons away with his excellent aim. The victorious Maximals returned to the Axalon with an evergreen tree. 
Soon, while retrieving a set of stasis pods on the coast of Africa, the Maximals set off one of the aliens' traps. Optimus Primal sacrificed himself to destroy the trap in a transwarp explosion, leaving Echowarrior in charge. Echowarrior was sad to lose his former commander and friend, though he was thankful that his efforts had brought the Maximals new forces such as Orchanoch, Cybershark, Claw Jaw, and Armordillo. To help relax himself after this blurr of events, he and Cybershark travelled back to Alaska to a lone island where a magical door to the Captain's Table was located. Here, he told the story of Primal's sacrifice to Captain Kirk, Captain Calhoun, and others. Captain Sisko agreed that it was "a tale fit to be a Shakespearean play." 
Echowarrior was responsible for even further additions to the Maximal roster, such as the Japans: Power-hug, Diver, and Mantis. Megatron likewise built up his own Predacon army.  A massive ship crashed in the Himalayas, containing even more warriors for each side. Echowarrior and Megatron reached an agreement -- allow the Predacons to claim four of the five of their own among the crashed, and the Maximals could have the fifth.