Possible Clues:

• Creature with eight tentacles
• The work of one month had one well-armed
• A firm turn to matter for this army affair?
• Work by the month for this influential organisation
• Cops out (anag.)
• Relative of a nautilus
• They're up in arms - all eight of them - for work for a month
• Ocean dweller with a beak
• Five Irish poems
• Marine inhabitant has a month at work