Crusader

"Suit of armour generally possessed by a ghoul, ghost or spectre."

- Folio Bruti.

A crusader was a Roman Catholic knight engaged in the Crusades in the Middle Ages, against Muslims, pagans, heretics, excommunicated peoples.

There were many crusaders suits of armour at Hogwarts School of Witchcraft and Wizardry under spectral possession. They could be aggressive to passers-by, but were particularly vulnerable to the Incendio and Glacius spells.

Appearances

 * Harry Potter and the Prisoner of Azkaban (video game)