The Rubble is an enemy in Chrono Trigger that first appears in the Mountain of Woe in 12000 BC. Later, it can also be encountered at Giant's Claw in the Middle Ages.
They are a great source of EXP and TP. They do not, however, respawn when leaving the current screen and re-entering. They have a very high evade, so equipping items such as the Acuity Ring or Berserker Ring is recommended. Every tech and item will be disabled when initiating combat, and the player has a limited amount of turns before they escape.
Gallery
Rubble's entry in the Character Library.