You may also find Giant Ant. Each of their wings you hunt will absorb one trap in the Porte Forest Path (trap room).
If you plan on doing this quest with less than three people you will need 6 Giant Ant Wing per person.
Continuing
When you reach your target number of roots and manes head back to Torbjorn and say "Porte Forest" again.
He will take the Trent Root and tell you where he last saw the Turuc Pendant.
Form a line and take it slow. If somebody skulls make sure to red them before continuing up the path.
Near the middle there are two traps right next to eachother so you will need to react quickly.
When you reach the end enter the Porte Forest Peak Waiting Room to let your group's Health and Mana regenerate.
When you are ready to fight have one person enter the next room and the group will be teleported in.
The Giant Mantis will immediately appear and after a few seconds become hostile.
Giant Mantis can reduce you to 1 Health constantly if you don't have a Silver Wolf Leather.
It can be killed with Rogue damage traps, or by a half decent Warrior.
It has elemental defense so use Dark attacks.
If there is a subclass in your group it should be a little easier.
You will receive a Tristar Ring and the Legend Mark: "Saved daughter of Porte Forest"
You may to speak to Lureca in Porte Forest Shop to give him the Tristar Ring for an extra reward of 1,000,000 Experience and the Legend Mark: "Eased the suffering of Porte Forest". If you later decide to give him the ring you can always walk back to Porte Forest Shop in Porte Forest 3-C