Ankheg Plate Mail is a rare type of body armor. It's crafted from the shell of an Ankheg and as a result is bright green. Ankheg armor is as strong as Full Plate Mail, but as light as Studded Leather Armor. It has an armor class of 1 and offers additional armor class -1 against piercing and missiles and -3 against slashing attacks. This plate mail can be worn by druids. This piece of body armor gives better protection than most of the plate mails; all pieces of full plate mail are better, but they all weigh more. It requires a strength of 8 to wear it.
In Baldur's Gate, to get your hands on a set of Ankheg Plate Mail, slay an Ankheg and take its shell to Taerom Fuiruim at the Thunderhammer Smithy in Beregost. He will charge 4000 GP for him to craft the shell into armor. Come back about 10 days later, to collect your shiny new armor. In BG:EE it costs 4000 GP for him to craft the armor in 3 days, or you may pay 6000 GP to have it ready in 1 day. Regardless of which version of the game you have or how fast you want your armor made, Taerom will only craft 1 piece of Ankheg armor for your party; afterwards he will only buy Ankheg shells for 500 gold. At a farm patch in Nashkel, you can find another set of Ankheg armor.
It is one of the best suits of armor available to druids in the original Baldur's Gate. It's low strength requirement of 8 also allows weaker NPCs like Viconia to wear it and gain decent protection. Its low weight of 25lb makes it a good back-up armor for Fighter/Mages and Mage/Clerics to keep in their inventory and put on once they have exhausted their arcane spells, in order to survive better in melee.
To obtain this armor in Baldur's Gate II, bring a shell to Cromwell in the Athkatla Dock District. He will charge you 5000 gold to make the armor and you need to help him for a day. You can do this more than once.
This plate mail has been expertly crafted for you by Taerom Fuiruim of Beregost. Sheathed in the chitinous scales of the Ankheg, it provides a greater degree of protection than traditional plate mail and is not susceptible to rust. As any world-weary adventurer will tell you, however, the best appreciated aspect of ankheg mail is its light weight and low encumbrance. Monsters come and go but fatigue is a constant enemy.