A Predacon "serving" under Megatron, Tarantulas can transform into a spider. He is cold calculating, and manipulating.
Tarantulas is a member of the Predacon Secret Police, he acts as a mole in Megatron's crew(sending information Tripredacus Council). He shares the same origin as the council and had the original intent or going back in time to alter the timeline, by destroying the Ark. There was a set back when he and the rest of Megatron's group were sent to unidentified planet and all connection to Cybertron was lost. Tarantuals carried on with his plan despite the obstacle.
Since Tarantulas was Megatron's technical leader he manned the scanners for the Predacons. For himself he chose the form of an oversized spider. He took part in the first battle against the Maximals, but had an energon buildup while the Maximals were escaping. Later on the Predacons found a stash of energon crystals on a mountain and were forced to be in their beast modes. Tarantulas fought Rattrap while they were both in their beast modes, until the energon blew up due to a chain reaction set up by Megatron.
Eventually Tarantulas made his own secret lab, to keep his inventions from Megatron's wandering eyes. Tarantulas managed to capture the maximal Cheetor in one of his webs, after helping Scorponok with recovering the omega canon. Cheetor was leter saved by Rattrap. During the battle at Standing Stones Tarantulas was blasted by Rattrap. He later went with Megatron and Terrosaur to attack the Axalon, but they were defeated by the Maximals after Optimus Primal was restored from an alien probe.
When Terrorsaur defeated Megatron in combat he put Tarantulas in charge of the predacons before leaving. Tarantulas wanted to know what Terrosaur's new power source so he followed him to a flying mountain with super energon on it. Tarantulas saw Rattrap on the mountain and two began to fight, which lead to Tarantulas falling off the mountain. After a stasis pod crashed Tarantulas took part in an attack on the maximal's base. He was blasted away by the base's auto guns.
Eventually the predacons found a stasis pod and Tarantulas gave it a spider beast mode making Blackarachnia. Tarantuals eagerly followed Terrosaur during his second attempt at taking over the predacons(this time they were aided by Rattrap). He found Rattrap, but was blasted by the maximal. He went back to the predacons only to find that Megatron was leader once again. During a berserker Optimus Primal's attack on the Predacons base Tarantuals was pinned to a wall with his own invention.
The transformation lock lens created by Tarantulas was key in preventing the Maximals from contacting a temporal probe. Tarantulas used his invention to trap Cheetor and Tigatron and then wreaked havoc in the Maximal base, before he was stopped by Primal. Despite the invention being destroyed the Maximals could not make contact with the probe. When the Predacons found a Maximal spy camera in their base of operations they faked a mutiny and hid in a crevice. During this time the Maximals were fixing the Axalon and the Predacons were discovered by Dinobot. The Predacons and Maximals fought for the Axalon, but the battle was short lived when the ship crashed. After the Maximals won Tarantulas managed to capture Rhinox.