Like so?
Venomous Ink Cloud (Ex): A Zakharen kraken can emit a cloud of jet-black ink in an 80-foot spread once per minute as a free action. The cloud provides total concealment, which the kraken normally uses to escape a fight that is going badly. Creatures within the cloud are considered to be in darkness.
The ink cloud contains a deadly contact poison, and is equally effective on land and underwater. The cloud persists for 1d4+1 rounds in either case.
Zakharen kraken venom: Contact, Fortitude DC x, initial and secondary damage 1d6 Con. The save DC is Constitution-based.