From Pathfinder Howl of the Wild, which isn't enabled.

Hexworm

CREATURE 4

These gray larvae inch across the ground with an instinct to feed on magic.

Perception +10; arcanosense (precise) 60 feet

Skills Acrobatics +10, Arcana +12, Stealth +9

Str +2, Dex +4, Con +3, Int -5, Wis +1, Cha +0

Arcanosense

A hexworm can sense sources of magic at the listed range as though it has a 4th-rank Detect Magic constant innate spell.

AC 20; Fort +11, Ref +14, Will +6

HP 45; Resistances spells 5

Arcanovore

A hexworm has resistance 5 against all damage caused by spells.

Speed 20 feet

Melee Mandibles +8, Damage 2d6+2 piercing plus Arcane Consumption

Arcane Consumption

The hexworm attempts to consume the magic of an adjacent magical effect or unattended magic item. It attempts a counteract check against the target with a +11 modifier. On a success, the magical effect ends. A magic item instead becomes a mundane item for 1 round. The hexworm gains 2d8 healing Hit Points.

Arcanotaxis

Requirements The hexworm has detected a source of magic with its arcanosense

Trigger The hexworm's turn begins

Effect The hexworm Strides up to its Speed toward the nearest source of magic it can detect.

Pathfinder Howl of the WildORC