Briarwood Reed
The Briarwood Reed was a trinket that dropped from the rare spawn Jed Runewatcher in UBRS. At launch, when everyone thought spell power was bad, the trinket was largely ignored. However, after the potency of spell power had been realized the trinket was so sought after that it was common for a party preparing to do an UBRS run would often reset the instance until Jed was up (you could target him from the entrance of the instance). The Briarwood Reed just made any caster better. This in a world where lvl 60 players would regularly wear their Argent Dawn Commission and the Mark of the Chosen because there just weren't trinkets that mattered. Many dps casters and healers would use this trinket for months after acquisition. The only trinkets that would eventually be better than it would come with the DM patch (Mindtap Talisman, Royal Seal of Eldre'Thalas) and eventually in raids (Neltharian's Tear, Rejuv Gem). Mow was totally unable to obtain this on Nost.
