Slimmerman was a malevolent artificial intelligence inadvertently downloaded to the League of Freedom’s Robobot. A firewall took care of the problem but not before a good time was had.
References: [Supermansion] [2015 – 2019] [Season 2, Episode 12, Drag Me To Halloween: internet ghost meme that downloads and possesses Robobot; “Robobot is gone. There is only Slimmerman.”; ]
Metahuman Database 