Flagstaff with the Coat of Arms

The  is a fort object introduced in the 13.0.0 update.

Appearance
It appears to be a red clan flag with a skull on the top, two skulls under it and a zombie head, which are all over a golden stand.

Use
It shows the logo of the player's clan on the battlefield.

Trivia

 * It is the fort object with the longest name.