Toltec Familiar (3.5e Feat)
From D&D Wiki
Benefit: By touching your familiar you can transform it into a handheld object that weights no more than one pound. You may choose the material that the object is made out of each time you transform your familiar. When your familiar is in this form it does not need to consume food or drink.
Normal: Your familiar's form cannot be changed except by a spell, spell-like ability, or super natural ability.
Special: Your DM may let you apply this to a animial campanion, special mount, psycrystal, etc...