Possible Clues:

• Is one fully armed for monthly work?
• Invertebrate with three hearts
• That might be army work for the autumn
• Sea creature with eight tentacles
• Creature with eight arms
• From influential organisation, old copper's nicking head
• Autumnal work for army type?
• With principal made redundant, centre visited by head in large organisation
• Army type in appalling cop-outs
• Well-armed character that squirms when caught