From Friday, September 22nd to Sunday, September 24th, you can earn free Crown Crates just by logging in and defeating a monster or minion. You can earn up to three Reaper's Harvest Crown Crates that can see you take home some brand new items including mounts, pets, costumes, consumables and even an ultra rare mount like the Plague Husk Horse or Cinder Wolf Mounts.
Tamriel's covens of witches and warlocks spent all year crafting necromantic objects of dark delight for the season of the Witches Festival. The sale of these occult oddities and twisted treats are usually restricted as contraband goods, but in honor of the Witches Festival they may be freely sold or given as gifts. (Please note that the merchants of Tamriel will not accept responsibility for curses bestowed or injuries sustained through the use of these arcane artifacts.)
You can check out the full list of items that can be contained in a Reaper's Harvest Crate or head to the Elder Scrolls Online site to see them in full color.