Second half of the reference page for Bahamut, this has more detail.

Some of his physical abilities include above-average strength, multiple arms, the fact that every limb (even legs) end in extremely dexterous hands, and being able to use all parts of his body with the maneuverability as you would your fingers.

In terms of other abilities, he can shoot poison from his mouth, and as seen in the second side-profile head, turn into one of the freakiest things you've ever seen. However, when in that form, the secondary eyes above his normal ones open, shining light that causes random destructive effects on whoever looks at it.

Wee.

Oh, and the cloak/straightjacket is what he was found in.