Because sometimes you just need a CR 1 ooze. Or a swarm of them.
First-year wizarding students at Veltan Academy produce their share of rudimentary potions—and mistakes. The sewers beneath their workstations are now swarmed with amoebas, some of giant size.
Will-o'-wisps have been reported in the swamp just outside of town. The truth is less dangerous, but by no means benign—amoeba swarms, grown fat on the local phosphorescent microbes, glow in the night as they hunt.
Myer Landsdowne went to his grave clutching the amulet inscribed with the location of his fortune. But the illness that killed him continued to feed on his corpse. Now his sarcophagus contains only a giant amoeba.
—Pathfinder 2 24