In an unusual move by the Magic: The Gathering Pauper format panel, a Modern Horizons 3 Artifact Equipment was added to the Banned and Restricted list before the set's release.
Every BAN in MTG Pauper History Explained in Under 10 Minutes
Prebans are not normal in MTG, but with a set as powerful as Modern Horizons 3, what was normal is no longer normal. The first preban targeted 13 Magic cards for the MTG Arena Historic and Brawl formats. A second preban was announced on June 6th by principal designer Gavin Verhey, who is also a member of the Pauper Format Panel (PFP). Many in the MTG community mentioned it when Cranial Ram was previewed during MH3 spoilers , and today it became official, with Artifact Equipment being added to the MTG Banned and Restricted Pauper list.
The decision to ban Cranial Ram on an emergency basis is “unprecedented” and “not something players should expect to see again in Pauper or any other competitive format anytime soon,” according to Verhey.
So why did the PFP choose to ban Cranial Ram before MH3 even came out? The Living Weapon is similar to Cranial Plating, which has "dominated multiple formats throughout Magic's history," according to Verhey, and is similar to All That Glitters, which was recently added to the MTG Banned and Restricted Pauper list.