During the time of Egypt's pharaohs and their rule, Sammun-Mak gained control and ruled with a rather cruel reign. This was not helped by his contact with the Toys of Power which granted those with psychic powers incredible abilities like seeing into the future and shape-shifting. Unfortunately, Sammun-Mak had these psychic powers and abused the Toys of Power to cater to his childish whims and arrogant wishes.
He also was quite the sadist who did not take kindly to any criticisms. During an early moment, Sammun-Mak mentioned that he had a lute teacher fed to a crocodile for "daring to criticize his divine embresure".
The mole populace rebelled against his tyranny and eventually took him out using a brain screw. His disembodied brain eventually ended up in Papierwaite's possession in the Museum of Mostly Natural History and was found by Sam during his search for Max's brain.
They Stole Max's Brain!
After General Skun-ka'pe steals Max's brain, Sam goes on a path that leads to the Museum of Mostly Natural History. There, he encounters the disembodied brain of Sammun-Mak and puts the pharaoh's brain in Max's body to keep it from being thrown out as being trash. Wowed by modern day devices and such, Sammun-Mak eventually gets into the Toys of Power. Claiming Max's body and the Devil's Toybox for himself, Sammun-Mak completely rewrites reality to fit his favor.
In the alternate reality, Sammun-Mak is a horrific tyrant who has everyone, save Max's brain, enthralled to his whims. He organizes several gladitorial matches wherein Skun-ka'pe beats and murders dissidents. Particularly, Sammun-Mak arranges the attempted genocide of all mole people as a revenge against them for their past murder. Max's brain directs Sam to collect three badges to get in Sammun-Mak's inner circle and to get close with the brain screw. After defeating Skun-ka'pe, Sammun-Mak himself steps into the ring to kill Sam. Tricking Sam into kneeling and saluting as a loyal subject, Sam drives the brain screw into Sammun-Mak's brain, removing him from power and restoring reality to its former state.
Sammun-Mak's brain survives the events and is taken as a power source on Skun-ka'pe's ship in The City That Dares Not Sleep. His brain is onboard when the ship is destroyed by the demonic Max teleporting to it to keep an embedded warhead from destroying New York.