n medium earth elemental 

Perception +12; darkvision, tremorsense (imprecise) 60 feet

Languages Terran

Skills Athletics +14, Stealth +8

Str +5 Dex -1 Con +4 Int -2 Wis +1 Cha -1

Earthbound When not touching solid ground, the living landslide is slowed 1 and can't use reactions.

AC  21; Fort +15, Ref +8, Will +10

HP 90; Immunities bleed, poison, paralyzed, sleep

Crumble [R] Trigger The living landslide takes damage from a hostile source while atop rock or earth. Effect The living landslide crumbles into the ground, Burrowing down 10 feet. This Burrowing does not trigger reactions. The living landslide can't Crumble again for 1d4 rounds.

Speed 25 feet, burrow 25 feet; earth glide

Melee [>] fist +16 (reach 10 feet), Damage 2d8+8 bludgeoning

Earth Glide The living landslide can Burrow through any earthen matter, including rock. When it does so, the living landslide moves at its full burrow Speed, leaving no tunnels or signs of its passing.

Bestiary, page 146. Expanded in LOIL.