Quickclay

Quickclay was a type of sticky, green-gray soil prevalent on Mimban (formally called Circarpous V). It was a hazard because it gave way easily under pressure, which could result in an object or individual being sucked in and becoming trapped in it, much like quicksand. It was harder than mud or sand, and more like clay.

Quickclay, imported to her Tatooine palace from the planet Circarpous V, was placed among the exotic (and mostly predatory) flora and fauna of Gardulla the Hutt's pleasure garden. Young Anakin Skywalker, fleeing from sinister trackers in the garden, stumbled into a quickclay patch, sinking his arm up to his elbow in the greenish goo but managing at last to extract himself from it. It went a bit worse for the bumbling Abyssin cyclops giant Gondry, however, whose huge gangling body sunk to its armpits before Anakin threw it a tree branch and helped free the witless monster from its would-be grave.

After crash-landing on Circarpous V, Princess Leia Organa became trapped in a patch of quickclay, but she was rescued from it shortly thereafter by Luke Skywalker, R2-D2 and C-3PO.