High Quality Content by WIKIPEDIA articles! Sentinel Prime is the name of several fictional characters in the various Transformers series. First mention of Sentinel Prime was in issue #65 of the US Marvel Comics Transformers series, where he was mentioned to hold the Autobot Matrix of Leadership before Optimus Prime. Sentinel Prime has since appeared in a variety of forms as either Optimus Prime`s mentor or friend. Fun Publications has also had a character in their comic called Sentinel Major, who is based on the Transformers Animated version of Sentinel Prime.