Cloak of the Sewers

Cloak of the Sewers offers the wearer a bonus to armor class of 1 and once per day, the wearer can shapeshift into a rat, mustard jelly or a troll. This item appears in Baldur's Gate II: Shadows of Amn. It can be found in the Athkatla Sewers underneath the Athkatla Temple District.

In-game description
"Cloak of the Sewers: For a sewer dweller like Ivan, survival meant going where others refused. Hiding from thugs, Ivan went so deep into the sewers beneath Baldur's Gate, that he found caverns of natural caves, some of which opened to the ocean. Within one cave, Ivan discovered what he thought was a ruined cloak, all torn and stained. He tossed it into the fire he started, but it would not burn. Curious, he donned it and with some prying he discovered its hidden abilities. With the right command he could shift into a rat, a troll, or a mustard jelly."