The Secret Files of Teletraan II were several short segments tacked onto the end of certain episodes of the third season. They were created to fill up any episodes that were running short, and give viewers information about things like the Autobots, Decepticons, Quintessons and more.
Each segment was narrated by Victor Caroli.
Autobots
Cassette Transformers
Decepticons
Metroplex and Trypticon
Predacons
Quintessons
Ultra Magnus