Punishment three. Manannan sentences Gwydion to aerobics in the entry hall.
In the three bears' house, Gwydion tries the smallest chair. It does not survive.
The big one. Manannan sits down to a bowl of porridge laced with the cat cookie, and Gwydion's master is a housecat for the rest of his days.
Punishment two. Manannan strings Gwydion up from the kitchen ceiling to think about what he's done.
With Manannan away in town, Gwydion moves a book on the study shelf, works the lever behind it, and a trapdoor opens onto the stairs to the laboratory.
Manannan turns in for the night, and every Z he snores is a minute Gwydion can spend snooping.
Punishment one. Manannan turns Gwydion into a snail and leaves him to crawl the upstairs hallway.