Latch On

When the Latcher attaches itself to a willing host it is considered bonded to the creature and cannot move, take actions and is immune to all damage. The Latcher can remain attached until the willing host loses concentration (as if they were concentrating on a spell). While bonded, the Latcher acts as an additional arm for the willing host. It can manipulate an object, open or close a door or container, pick up or set down a Tiny object, perform the somatic components of a spell cast by the bonded creature, or wield a weapon that has the light property.  

Magic Resistance

The latcher has advantage on saving throws against spells and other magical effects.