Clay for the Struggling Artist
From Jenny Everywhere Wiki
Madame Tarsa's Clay for the Struggling Artist was a clay-like substance created from shiftstones she imported from Swaatch. The clay would spontaneously reshape itself in the image of whatever touched it.
Tarsa used her last batch of Clay for the Struggling Artist to create the Clay Thing, turning it from an inanimate lump of magical substance into an actual living being by embedding a Life Crystal within it. After the Clay Thing was destroyed by Pessimist's Fog Ship to save Larrikin-1029 and Pessimist-242, Tarsa complained that she'd have to import more shiftstones from Swaatch to replenish her stock of Clay. (PROSE: The Toymaker's Labyrinth)
It was recognised as one of her most notable creations. (PROSE: The Frost King's Treasure)