As you come around the corner you spot a man-sized rock formation repeatedly bumping into a wall of solid stone. The creature notices you (One within 60ft, due to tremorsense) and turns to flee, dragging the right side of its body against the rock wall as it goes.
A DC 15 Perception Check will notice an differently colored stone on the front of the creature.
Monsters: Medium Earth Elemental [SRD Link]
Tactical Notes: The Elemental is scared. After it was summoned a gem was affixed to its chest to prevent it from returning. This gem has also mostly disabled its Earthglide ability (a 1 in 20 or worse chance that it works each round, probably shouldn’t bother rolling it but this helps explains how the Elemental got into its current area)). It will occasionally forget it can’t earthglide and bump into a stone object, regardless, at only a 20 ft move speed it should be fairly easy to catch up to. It will not strike unless it is struck first. If the PCs can corner it and remove the gem (DC 25 Disable Device, 20 Use Magic Device, or 20 Spellcraft) it will happily retreat into the earth.
XP Value: 600 xp (3/4 of the CR3 Elemental, due to its weakened state)
If the Elemental is successfully set free without harm he may place a few stray gems he finds along the path of the PCs as thanks.
A gem that once held a Permanent Dimensional Anchor-like effect. Now just a rough diamond worth around 250 gp.