Dreams can often reflect our subconscious thoughts and feelings, incorporating symbols and scenarios that might be connected to our waking life. In your dream, several elements stand out:

1. Filthy Bathroom: This may represent feelings of vulnerability or discomfort in your life. Bathrooms often symbolize a place of cleansing or release, so the filth could indicate emotional baggage or unresolved issues.
2. Blood and Crocodile Head: Blood can symbolize deep emotions, pain, or a life force. The crocodile might represent hidden fears or primal instincts. Together, they could signify a struggle with something that feels threatening or dangerous in your life.
3. Tsunami: This powerful natural disaster can symbolize overwhelming emotions or situations that feel uncontrollable. It might reflect a significant change or upheaval that you are currently experiencing or fear.
4. Green Land and Rising Sun: The transition to a green land and sunrise can signify renewal, hope, and new beginnings. It suggests that after facing turmoil (the tsunami), you are entering a phase of growth and positivity.
5. Only Underwear: Being in underwear can signify feelings of exposure, vulnerability, or a desire for authenticity. It might indicate a need to embrace your true self, stripped of societal expectations.

Overall, this dream seems to convey a journey from chaos and discomfort to a place of hope and renewal. It may suggest that while you are currently facing challenges, there is a potential for transformation and new beginnings. Consider reflecting on any recent changes or stresses in your life and how you can embrace the positive aspects that may arise from them.