Each Aberrant Horror is defined by one key question: what happened to them?
Some individuals make pacts with ancient entities for powers that have unforeseen effects. Others
awaken after being defeated by an unnatural monster, surprised that they have been spared, only to feel something writhing in their stomach.
Many tropes of body horror can be used as inspiration for an Aberrant Horror.
Once your origin has been determined, you can consider what your character’s motivations are regarding their transformation.
As their power grows and manifests, they may feel they have lost what makes them fundamentally themselves.
Perhaps they decide to take revenge on the entity responsible for their transformation, or perhaps they perceive their transformation as a gift.

An Aberrant Horror has the following
transformation features:
prerequisites
Ability Scores: Constitution 13
Roleplay: You must have had an encounter with an Aberration, magical anomaly, or some other plausible reason to have become an Aberrant Horror.
Discuss with your GM how you can achieve this in your backstory or in-game.
Some of your abilities will require your target to make a saving throw to resist their effects.
The saving throw DC is calculated as follows:

Transformation Save DC = 8 + your proficiency
bonus + your Constitution modifier