Boelox

Amorphous. The boelox can move through a space as narrow as 1 inch wide without squeezing.

Reversed Magic Resistance: The strange and unknown ways in which the boelox was created has granted it a mysterious magic resistance that defies all logic. The boelox has immunity to all spells above 4th level and similar magical effects on par with spells of such level. The boelox takes damage as normal from 3rd and 2nd level spells while having vulnerability to 1st level spells and cantrips. The boelox has vulnerability to common weapons and uncommon weapons act as normal. The boelox has immunity to weapons of the rare status or greater.

Spider Climb. The Boelox can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Devouring Evolution. If the boelox was to devour a mage it may gain access to some of the spells the corpse could cast in life. If the boelox was to devour a bird it would gain the ability to fly. In addition, if the boelox devours a creature that has an ability score 16 or above in any category the boelox's own ability score will increase by one for all the ability scores the creature had above 16. If the ability score of the creature is 20 or above, the boelox gains an increase of 2 in all of those abilities.

If the creature is of a size equal to or greater than its own it will go up one size category as will its hit die. The boelox's proficiency bonus will also increase by one for every size category.

Slashing Maw. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 3 (1d6) slashing damage. If this attack reduces the targets hit points to zero or less the target instantly dies. If this occurs, and the boelox has time to devour the corpse, it gains many of the special traits of the creature it devours.