Vana'diel Bestiary: Elder Treant  

These mobs aren't the best for a single NIN to tank, even with full evasion merits and a bard. They tend to strike with 1-2 branches in a single attack round. TP attacks include Drill Branch which is a 2-fold attack, and Leafstorm - AoE that wipes up to 3 shadows. There's also another attack that binds targets but ignores shadows. I'd only recommend merit parties for these, as I couldn't even hit these that well with +40 acc/sushi and 8/8 katana merits. They do give a nice amount of exp/kill though; 200+ on Chain#1, and tend to be the last mobs in the Mire that any exp party intentionally camps on(Assuming the staging point is packed to begin with).