Let's call this Mutation Quirk "StretchMorph." This Quirk grants the user the ability to stretch and morph their body parts, inspired by the Gum Gum Fruit from One Piece.

1. **Stretching Limbs:** The user can elongate and stretch any part of their body at will. This includes their arms, legs, torso, and neck. This stretching ability allows for increased reach in combat, agility, and the ability to interact with objects from a distance.

2. **Morphing Appendages:** In addition to stretching, the user can morph their limbs into various shapes. They can transform their hands into hammers, blades, or shields, adapting to different situations and combat scenarios. The versatility of morphing enhances the user's offensive and defensive capabilities.

3. **Rubberized Physiology:** The user gains a level of physical resilience similar to rubber. They can absorb blunt force impacts, making them resistant to conventional physical attacks. While they are not entirely immune to damage, this rubberized physiology provides a level of durability that exceeds that of a regular human.

4. **Gum Gum Propulsion:** By rapidly stretching and contracting their legs, the user can launch themselves into the air, achieving impressive heights and distances. This Gum Gum Propulsion adds an acrobatic element to their mobility, making them agile and difficult to predict in both combat and navigation.

5. **Selective Invulnerability:** The user can selectively render parts of their body invulnerable to pain or damage by stretching or morphing them. This allows them to endure attacks that would incapacitate others, strategically protecting vital areas during intense battles.

**Limitations and Drawbacks:**

1. **Gum Gum Strain:** Overusing the stretching and morphing abilities can lead to physical strain and fatigue. The more extreme the morphing or stretching, the more energy it consumes, requiring the user to manage their stamina carefully.

2. **Vulnerability to Sharp Objects:** While resilient to blunt force, the user remains susceptible to sharp objects like blades or piercing attacks. The rubberized physiology doesn't provide complete immunity against cutting or stabbing attacks.

3. **Limited Morphing Complexity:** The user's morphing ability is versatile, but there are limits to the complexity of the forms they can create. Elaborate or intricate structures may be challenging or impossible to replicate with this Quirk.

4. **Gum Gum Propulsion Control:** Achieving precise control during Gum Gum Propulsion requires practice. Accidental launches or unintended trajectories can result in the user overshooting their target or crashing into obstacles.

5. **Temperature Sensitivity:** Extreme temperatures, especially extreme cold, can affect the user's flexibility and resilience. In freezing conditions, the user might experience stiffness, limiting their range of motion and making them more vulnerable to damage.

"StretchMorph" offers a dynamic and adaptable set of abilities, blending offense, defense, and mobility. The user's creativity and strategic thinking are crucial for maximizing the potential of this Quirk while navigating its inherent limitations.