A Mario easter egg has been discovered in an old Sega Saturn game. A title released long before Mario and Sonic decided to team up and take on the video game world together.

If someone who had been in a coma since the early '90s were to wake up today, they would probably be pretty surprised to hear Sonic and Mario managed to settle their differences. Before we had ever heard of PlayStation and Xbox, it was Sega and Nintendo battling out for console dominance. Nowadays the two work together, its characters appearing alongside each other in various games.

It wasn't until late 2007 and into 2008 that Sonic and Mario started to appear in the same games together. First via Mario and Sonic at the Olympic Games, and then shortly after in Super Smash Bros. Brawl. That's why the discovery of a Mario easter egg in 1995 Sega Saturn game Astal is somewhat surprising.

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There's a reason Mario's unexpected presence in a Sega game has been hidden for more than 25 years. The plumber isn't simply there for any Astal player to find. The very grumpy-looking take on the Nintendo mascot, which is likely by design and intended to be a slight to Mario's creators, is hidden away in the game's files. You can check out how the hidden Mario looks in the tweet below.

“It is discovered that an image that seems to be Mario was hidden in 0xFE90 of APT.BIN on the disk,” the tweet reads when roughly translated. It's actually one of many shots Nintendo and Sega would take at one another through the '90s as their respective consoles battled it out. The blue hedgehogs in Super Mario World 2: Yoshi's Island are called Harry Hedgehog, and there's a Sonic children's book called Secret Admirer that features a sign which reads “No Nintendo Playing”.

There's also a belief that Sega sneakily snuck Mario into the first Sonic game on the Mega Drive. It has been highlighted a number of times that when color is added to their design, the ruins in Marble Zone appear to be small Mario faces. We can certainly see the resemblance, but even after all this time we're still not convinced it was intentional on Sega's part.

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