Rupert: Quicksand Scene
Season 4, Episode 3 Rupert and the Marsh Mystery
Two young animal children named Rupert and Ottoline were running from a man named Mr. Slyless Gromit who tries to stop them for telling Ottoline's aunt about the marina she's selling the inn. They accidentally fell into quicksand and Mr. Gromit leaves them while they fully sink until they were rescued by another animal child named Phoebe who heard their scream during being chased. Ottoline only sink towards her hips and Rupert sink to his neck when he tried to grabbing some kind of root stick he was trying to reach it to grab.