I typically rule that Hermetic spells and item effects to change a person into an animal also change the person's clothing, since most clothing is Animal (wool, leather). To transform an armored and armed character should probably include a Terram requisite, I think. I probably wouldn't require requisites for other small objects in the person's possession, like a knife, wine in a wineskin, ink in a book, or vis.
OK, so I only have one Terram requisite. It still costs about twice the level to shift the redcap's stuff than to shift the redcap and her stuff (HoH: TL p. 102, Shape of the Ancient Kite Mu(An)Co40)! Absurd, isn't it?
This is the item:
Enchanted Item: Ankle-Ring of the Shapeshifter
The Ankle-Ring of the Shapeshifter is a golden ring that transforms all the Shapeshifter's possessions into an intricate pattern on the ring when the Shapeshifter changes into a non-human form. The ring adapts itself to a size that fits the animal form.
Perceive the change InCo15, as in GotF, p.96 (Falke's Talisman); Level: 19
My Bjornaer plans to make a robe as his Talisman. A Talisman is considered part of the magus for magical purposes, so it should change with him. (Of course, he needs to invest the Talisman/robe with effects to keep it from wearing out or getting torn like mundane clothes do...)