oh yes! another thing that could have been mentioned somewhere... I played two entire games without knowing what these things did.
Throw away the cat.
The spider was good for a random chase, as Jurak said.
The frog, though - that's a keeper. When you're encumbered and can't run, just change into the frog. It's a SoW for DD. Just remember that you can't activate a portal or interact with any NPC's while small and green. (Just right click on the statuette again to cancel the morph.)
