While it may be odd that we are getting another exclusive Tarantulas in such a short time, they do indicate that this will be based on his Transmetal deco. As you recall, that body did have a motorcycle mode, however, he will not be using the deluxe Groove mold but instead the Rook mold as seen below.

Also, this means that the remaining three members of the combiner are probably the original members of the Tripedicus combiner: General Ram Horn, Sea Clamp, and Cicadacon.
Botcon wrote:10/09/2015 - We are thrilled to announce that Alec Willows, voice of the villainous and venomnous TARANTULAS from the Beast Wars cartoon series, will be our guest At BotCon 2016. Along with David Kaye, Alec will be available for autographs and panels as we celebrate the 20th anniversary of the Beast Wars.
Speaking of the robotic spider, we are also pleased to reveal that our second BotCon 2016 Predacon themed Combiner Wars boxed set character is in fact TARANTULAS, inspired by his season 2 "Transmetal" deco and featuring an ALL-NEW head sculpt. Along with Ravage, Tarantulas will merge with the other 3 Predacons in the box set to form PREDACUS!
Stay Tuned for more figure reveals, guest updates and info regarding events and registration for BotCon 2016 - North America's LARGEST Transformers fan convention!