Haiku Hitman is a challenge in Sawtooth Cauldron. To complete the challenge, players must find the four hidden ECHOs in Sawtooth Cauldron that tells Zero's story for coming to Pandora.
The first ECHO is located on a box on the right side of the road towards the Buzzards Nest from the fast-travel station.
The second ECHO is found in the open lands on a box.
The third ECHO is found in the Cramfist Foundry in the far end, after going up the stairs on the right and a set of ladders.
The final ECHO is found on top of the Buzzards Nest behind one of the huts.