The Sarlacc rests in the sandy well known as the Great Pit of Carkoon, buried except for its massive mouth and beaked tongue. The strange beast's lair was the site of many spectacles for Jabba the Hutt, who entertained himself by forcing prisoners into the creature's gaping tentacled maw.
Jabba the Hutt respected the Sarlacc and was curious about the creature, telling those sentenced to die in its innards that they would be digested over a thousand years.
After Han Solo accidentally activates Boba Fett's jetpack and sent him caroming off the side of Jabba's sail barge, the dazed bounty hunter tumbles into the Sarlacc's maw and vanishes from sight.
The Sarlacc senses Lando Calrissian trying to escape its pit and shoots out a tentacle, wrapping it around Lando's leg and dragging him back toward its hungry, tooth-lined mouth.