Gather tar for a trap - go to the Tar Pits of Inevitability at ( -892, 30, 296 ) /waypoint -892, 30, 296, kill a viscous tar elemental, then left-click its corpse to harvest tar. NOTE: The previous instruction appears to be wrong. Mouse over the tar pit (maybe after you killed a tar elemental, maybe not) and you will get a hand icon to harvest the tar.
Gather deino bones - left-click the bones sticking out of the tar pits
Return to Guldri at the docks
Speak to Yurwri at ( -712, 14, 259 ) /waypoint -712, 14, 259
Use the Deinodon Tar Trap on a rampaging deino. Once you do it will fall over and Yurwri will examine it.
Take Yurwri to Finze ( -689, 27, 151 ) /waypoint -689, 27, 151
Gather 6 gendri stalks from the Bawgava Tidepools - they're easy to spot, look for tall green reeds growing in the pools of water