Infernal Tack

The bridle, saddle and spurs we found on Haruman's nightmare after we killed it. Looked very valuable. It is. See Mission 11 - Haruman's Hill.

[!example]- Mechanics (Descent into Avernus)
Wondrous item, legendary (requires attunement by an evil creature). Binds a nightmare to the wearer of the spurs. As an action, clash the spurs or scrape them through blood to call the nightmare, which appears at the start of your next turn within 20 ft, acts as your ally, and stays 1 day. If it dies, it reforms in the Nine Hells within 24 hours. The tack doesn't conjure a nightmare; one must first be subdued so the tack can be fitted. Source: Descent into Avernus, appendix C.

#item