The Praetorian's hat (formerly and properly known as Knuckles' hat) was formerly a hat worn by the guardian known as Knuckles in one of the alternate dimensions in the Archie Sonic Universe known as MxYL or Light Mobius. However, the hat will be reused and renamed as the Praetorian's hat in an attempt to make Ken Pender's spin-off comic somehow connected to Archie Sonic universe.
The hat actually first appeared as a type of hat worn by Knuckles in the Sonic OVA, so it is likely owned by the OVA's producers, Pierrot, and was distributed by ADV.
In the comic and OVA, the hat resembled the ones worn by sheriffs, but included multiple stars-badges on it. It was stated by Penders that he changed the number of stars reasoning that it was enough to make it different while at the same time claiming it is not a rip-off.
Ken is attempting to make wearable replicas of the hat BEFORE the Lara-Su Chronicles (supposed) planned release date, because he loves to get as close to the rip-off line as possible!
It also looks like the hat worn by Portgas D. Ace, having the exact same size and shape amongst things.