[Sephie]

Alternatively, transformations into fungus (actual fungus, not just their fruiting bodies) tend to be fairly uncommon. In order of frequency it seems to go Animals, Inanimate, Plants, Fruiting Bodies of Fungi, Actual Fungi.

The best plants to do are often those at either end of the spectrum of complexity. The bladderwort is a highly evolved carnivorous plant that lacks leaves and roots. On the other hand Lithops are just roots and leaves (and flowers). Both would make for interesting transformations.

For animals Vertebrates tend to get over played. Amongst invertebrates insects and other arthropods are well represented so if one was to do an invertebrate do something like those mentioned in the first four propositions by Seadog Driftwood.

Amongst vertebrates mammals are the most frequent. It is my opinion that birds are the most underrepresented class of jawed vertebrates.