House of Slytherin Gadsden Flag
The house of Slytherin is one of the four divisions at Hogwarts. Its emblem is a snake. Thus it makes a good fit for a Gadsden Hogwart's Flag.
This flag is based upon the Gadsden Rattle Snake flag but with arms of Slytherin and 'TREAD' is changed to 'CAST A SPELL.'
'When Harry meets American Patriotism'
The Modern Gadsden Flag