For every successful wizard experiment or intensive magical study there are dozens of failures first—sometimes resulting in unintended creations! This entry in the Monstrous Menagerie series features a trio of creatures that might emerge from an alchemist's laboratory or mage's study: the artificially-immortal gestalt mage (CR 16), thirsty but feisty living cauldron (CR 4), and the entangled magic-begotten spell knot (CR 5). Dauntingly designed by Marc Kenobi, illustrated by Yeysson Bellaiza.