Retro Toy Chest: Remember Major Matt Mason? (1966)
Mattel, seeing the popularity of Hasbro's original G. I. Joe, decided they needed their own heroic action figure for young boys. So, in 1966, the company introduced Major Matt Mason, an astronaut. However, Mason's lifespan on the shelves wasn't very long. I have no memory of seeing any Mason toys in the stores as a teen, so I'd wager Mason was sent into permanent quarantine sometime in the 70's.
Apparently, the mindset at Mattel was that because Mason wasn't somehow linked to Barbie, his line wasn't selling. Then again, kids preferred Joe to Matt. Period.
Here's a sample ad, narrated by Marvin Miller (ex-The Millionaire)