Your dream seems to be rich with symbolism and themes that may reflect various aspects of your life. Here are some interpretations:

1. Transformation and Adaptation: The sudden appearance of small crabs may symbolize new ideas or projects that are emerging in your life. Crabs can represent resilience and the ability to adapt to different environments. This could suggest that you are undergoing changes or that you are nurturing new aspects of yourself.
2. Fear of the Unknown: Leaving your room to avoid the small crabs crawling on you could indicate a fear of being overwhelmed by these new developments or responsibilities. It may reflect your desire to maintain control over your personal space and comfort.
3. The Feline as a Representation: The transformation of your pet crab into a humanoid feline may signify a deeper understanding of your own identity or aspects of yourself that are evolving. Felines often represent independence and curiosity, which could suggest that you are exploring new facets of your personality.
4. Diet and Health Consciousness: The discussion about calories and the feline's vegetarianism highlights concerns about health, choices, and perhaps a desire for simplicity. This could suggest that you are contemplating your own lifestyle choices or are feeling the need to be more mindful about what you consume, both physically and emotionally.
5. Communication and Understanding: The fact that you pretended to understand your crab’s explanation could indicate feelings of uncertainty in your waking life, where you might be trying to navigate complex situations or relationships without fully grasping them.

Overall, your dream may reflect a journey of self-discovery, adaptation to changes, and a quest for understanding both yourself and the dynamics around you. It might be beneficial to take some time to reflect on your current life circumstances and how you feel about the changes you are experiencing. Exploring these themes further could help you gain clarity and confidence in your path forward.