3.5 Trinkets.
There are quite a lot of trinkets for Feral Druids. And again, for every role there are other better trinkets available. I left out the HC raid ones for now. Also note that for every “vicious” item I link, there’s a “bloodthirsty” version (for honor only) available as well.
Arena. (any bracket, any setup)
Vicious Gladiator's Medallion of Tenacity (340 Resilience). Standard PvP Trinket.
1v1, BG, World PvP.
Vicious Gladiator's Medallion of Cruelty (340 Crit Rating). Standard PvP trinket again but in this case it’s the Crit Rating version. The Resilience one will do fine as well but in my opinion you don’t really need the extra resilience in 1v1, BG and World PvP. Can work in a 2 DPS comp in 2v2 as well.
Either one of these is what you should always use. Next to these trinkets, you’ll have a few viable options:
2v2 (any setup), BG, World PvP.
Vicious Gladiator's Insignia of Conquest. I don’t like the RNG proc, but it has a pretty nice
uptime of 33% with a 15% proc chance and a 1 minute ICD. It’s comparable to roughly
~304 Agility.
Vicious Gladiator's Emblem of Tenacity. Could be a real lifesaver. Decent trinket but I wouldn’t take this trinket over the Insignia of Conquest.
Vicious Gladiator's Badge of Conquest. On use Agility instead of a proc, and although the Agility gain is a lot higher, the uptime won’t be. Your uptime with this trinket if you use it every single CD will be
~16,7% max and you won’t even ever reach that.
On the other hand, you can control your burst better with this trinket. Using this in combination with Berserk can be a real killer.
Unsolvable Riddle. Same story as the Badge of Conquest, this trinket is mostly good for burst. Overall, you’ll gain less from it than the other abovementioned trinkets but the big amount of passive Mastery makes it a very nice trinket. I’d rather take this one than any of the abovementioned trinkets.
Darkmoon Card: Hurricane. Quite expensive, but really nice. Arguably the best trinket we’ve discussed so far. If you got the money, and you’re willing to spend it…go for it.
The actual in game version shows that it does 5k damage, rather than 3750-6250. Crits seem to go up to 11k according to various sources, but I haven’t tried this myself yet. It procs about once every 12-15 seconds on dummies, so in PvP it will obviously proc a bit less often. It seems to have no IDC. I can’t really judge the yet, but overall it seems to be an awesome trinket.
Unheeded Warning. Insane damage increase. 321 Passive Agility is really good, and the proc actually gives a pretty huge damage increase for Ferals as well.
Mirror of Broken Images. This was a great trinket for 3's and 5's already before 4.0.6, but now probably also worth it for 2's. (Due to the shapeshift nerf mostly). If you're facing a melee-team, basically all it gives is the Mastery, but against a Caster-team it's an awesome trinket. I'm switching between this one and Unsolvable Riddle for 2's as well atm.
3v3 and 5v5. (any setup)
Arguably the best 3v3 and 5v5 Trinket as a Feral Druid is the one mentioned above as well:
Mirror of Broken Images
This trinket is basically a second Barkskin
for spells. 400 resistance means you’ll take about 40% less damage from spells (minus SpellPen). Most casters will have or sit close to the hard cap but even if they do it’s still a good , that’s still a good ~18-22% less spelldamage taken for 10 sec on a 1 minute CD. For 3v3 and 5v5 brackets where you’ll see casters 24/7 it’s a pretty amazing trinket.
The earlier mentioned trinkets for “2v2, BG and World PvP” are all viable for 3v3 and 5v5 as well. However, this one is probably far better than any of those.