Bergious minimus

Attunement to earth . Is has enhanced sensitivity to vibrations of the ground and is able to assess the density and type of material it comes across.

Enhanced echolocation. The creature has a multi-frequency ability to sense it's surroundings (movement, creatures and objects) and can "see" up to 120 ft. clear or 240 ft. vaguely. 

Extremely acid stomach. When a creature ends up in its mouth, esophagus or stomach, the victim has to roll every turn a CON save [DC 18]. When the victim fails the roll (or rolls a fail with acid resistance), it takes (2d4+3) acid damage. When a victim with acid resistance succeeds a roll, or is released from its predicament,  they get at the start of its turn 1 HP of acid damage until the acid has been neutralized with chalk powder, rinsed off with water or burned off with fire.

Cave of death. +3, 5 ft., The target has the opportunity to evade and has to succeed a DEX save [DC: 18]. On a fail, the target is in its mouth in the dark. With the next turn the target will be swallowed to the creature's esophagus. The turn after that it will be in the stomach. In all stages the target suffers the creatures trait "Extremely acid stomach"

Mountain of impact. +5, 5 ft., 7 (1d8+3) bludgeoning damage. The creature attacks with its full weight. The target gets knocked prone if the creature does a pass by attack or grappled when the creature is holding the target down.

Sonic boom. +3, 60 ft., multiple target in a cone., 8 (3d4+2) bludgeoning damage. Targets have to do a STR save roll [DC: 15]. On a success (or failed roll with bludgeoning resistance) the target get half damage and gets blown prone 10 feet away from the creature. If a target has immunity or has succeeded the roll with bludgeoning resistance, they are blown prone on the spot where they are. In any other situation they get full damage and are knocked prone 15 ft. away.

Slippery evasion. When a creature is in its favorite terrain, it can escape without triggering an opportunity of a attack.