Proportionate Wild Shape

(Masters of the Wild: A Guidebook to Barbarians, Druids, and Rangers, page 24, DnD 3.0)

[Wild]

You use wild shape to become animals of your own size, even if your wild shape ability would normally exclude that size category.

Prerequisite

Ability to use wild shape, natural form neither Small or Medium-size

Benefit

You use your wild shape ability to take the form of an animal whose normal size category matches your own. For example, a cloud giant druid (size Huge) with this feat could use wild shape to become a Huge shark or a giant squid.

Normal

The size of the animal form you can assume through wild shape is limited by the parameters of the ability, regardless of your original size.