Parasitic Offspring

Magic Resistance. The Offspring has advantage on saving throws against spells and other magical effects.

Limited Telepathy. The Offspring can magically communicate simple ideas, emotions, and images telepathically with any creature within 100 feet of it that can understand a language.

Parasitic Invasion. As an action, the parasite can dig into and under the skin of a target that is Paralyzed, Restrained, Stunned, or Unconscious. For 1 minute, at the beginning of each of the targets turns, the target must make a Constitution Saving Throw against the Warlock's Spellcasting Saving Throw DC. On the first failed save, the target suffers disadvantage to Attack Rolls and receives 5 magical piercing damage. On a success, the target suffers no effects.

During this minute the target can use it's action to attempt a Strength or Constitution check to attempt to remove the Parasitic Offspring from them. This check is made against the Warlock's Spellcasting Saving Throw DC. On a failure, nothing happens. On a success, the Parasitic Offspring effect stage is moved down one until it is removed.

If the target fails their first saving throw, at the beginning of their next turn they must make an additional Constitution Saving Throw against the Warlock's Spellcasting Saving Throw DC. On a failure, the Parasite digs deeper into the targets body and imbeds itself within them. If the target is not Stunned already it becomes Stunned. On a Success, the target suffers no effects. While Stunned, the target can still use its action to attempt to remove the parasite.

If the target fails their second saving throw, at the beginning of their next turn they must make an additional Constitution Saving Throw against the Warlock's Spellcasting Saving Throw DC. On a failure, the Parasite digs into the target even further and attaches itself to it completely. If the target is not Paralyzed already it becomes Paralyzed. On a Success, the target suffers no effects.

This Parasitic Offspring will eventually overtake the Host Body in a Week of time. After this point, the DM decides what this new Parasitic Host does, but the Parasitic Host has a friendly disposition towards the Warlock.

Creatures with a Challenge Rating above the Warlock's level make the Constitution Saving Throws with advantage.