Outcast - Second Contact

Travel to okasankar, head to fishing village and speak to sadar the fisherman, on your way to village kill a couple zeedar plants that spring from the marshes and collect their seed. When u speak to sadar you will already have the seed to give.

Voila! Achievement

This is found in the Okasanker, and Sadar is one of the Talan on the boats. Once you talk to him, he askes for a Zeedog gland, and these animals are the plant/snake things that are found South of the village. Once you bring him one, you'll get the achievement. Hope the video helps!