Bloodworm

Sand Tomb: When a creature is within 20ft of a surfaced blood worm their movement speed is cut in half until they exit the area of effect.

Razor Chitin: On a successful attack from a bloodworm the target must make a Constitution saving throw of 15+ or take the bleeding effect.

Thirst for Blood: Bloodworms are more likely to attack creatures that are under the bleeding effect. More instances of the effect draw their attention more.

Bleeding: When a bloodworm successfully applies the bleeding effect to a creature the creature takes 3 points of damage at the beginning of its turn per level of bleeding (Bleeding 3 = 9 points of damage). Bleeding can stack up to 3 times. The bleeding can be stopped by using an action to bind the wound. The binding requires something to use as a tourniquet and a medicine check of 15+ to succeed. All levels of bleeding can be fixed with one action.

Leaping Jaws: Bloodworm leaps at its prey attempting to wound it; +5 to hit, 15ft reach, 1 target. On a successful attack, the target takes 2d8 piercing + 4 points poison damage. 

Ripping Mandibles: The Bloodworm attempts to make the target bleed with 3 quick attacks; +5 to hit, 5ft reach, up to 3 targets. On a successful hit, the target takes 1d8 piercing + 4 points poison damage. The target must make a Con save for every successful hit.

Ravoness Feeding: The worm is hungry for blood (Can only be used on bleeding targets); The bloodworm attacks based on level of bleeding (1lvl = 1 attack). +7 to hit, 5ft reach, 1 target. On a successful attack, the target takes 3d6 piercing +  6 points  poison damage. 

Burrow: Bonus Action: The bloodworm can burrow underground using its bonus action. This does not provoke an attack of opportunity. Cannot be used when engaged with a bleeding target.

Keen Smell: When a creature takes a bleeding effect the bloodworm may choose to burrow and head for the creature. If the bloodworm is already attacking a creature that is bleeding this reaction will not take place. Roll for percentage to determine the outcome. Each level of Bleeding has a threshold for the action to take place. Bleeding 1=75%; Bleeding 2=50%; Bleeding 3=25%. Role the percentage dice, if the number rolled is above the threshold the bloodworm will attack the bleeding creature.