Story of the Tachash

Make a covering for the tent out of red dyed ram's skins,
and a covering of tachash skins above that.
-- Exodus, Chapter 26:14 --

At the time of the building of the Tabernacle, G-d told Moishe to use skins of animals to build the covering. Our sages teach that Moishe used the skin of a miraculous beast which had a horn and a many colored coat called a tachash.

It is said that Moishe put out his hand and this huge creature came to him, just for the occasion.

The coat measured 15 meters by 5 meters. Its coat was used to cover the Tabernacle and store the Holy Service Vessels. And, its purpose having come to pass, such a creature was never seen again.

More on the Tachash, courtesy of Rav Kook's Website