When you buy a certain amount of items from the vendors in the city gates area, you are given special items delivered to your house as Octavianus. You can access all of these by selecting them from your dresser.

Chameleon suit - Buy all items from all vendors
Crew Cut - Given from start
Mr. Onion Head - Buy at least 5 items
Pansa's Robe - Buy at least 10 items
Splitting Head Ache - Buy at least 20 items