This dream is rich with symbolism and emotion, and it seems to reflect feelings of fear, anxiety, and perhaps a sense of isolation. Here are some insights into the various elements of your dream:

1. The House: The house often symbolizes the self or your personal space. Locking yourself in may indicate a desire for safety and protection from external pressures or fears. It could also suggest feelings of being trapped or confined in a situation in your waking life.
2. The Darkness: The pitch black night represents the unknown, uncertainty, or fear of what lies ahead. Darkness can also symbolize feelings of insecurity or anxiety about the future.
3. The Animals: The presence of distorted or predatory animals, especially the horses and the tiger, suggests that there may be threats or challenges in your life that seem normal at first but have underlying dangers. Horses often signify strength and freedom, but their predatory features could indicate that something you once viewed positively is now perceived as threatening.
4. The Tiger: Tigers are powerful symbols of fear and ferocity. Your reaction to the tiger — the feeling of being chased and needing to hide — may reflect real-life stressors or fears that feel overwhelming. The tiger's wide eyes could symbolize a glaring truth or a fear that is hard to ignore.
5. Your Grandmother’s Indifference: Her calmness in the face of danger may suggest generational perspectives on fear or coping mechanisms. It might reflect how you view the responses of older family members to distressing situations, or it could indicate that you feel alone in your fears while others appear unfazed.
6. The Foggy Horses and Flame Creatures: These elements suggest confusion and chaos. The fog could signify unclear situations or emotions, while flame creatures might represent destructive thoughts or feelings that are present but not illuminating.

Overall, this dream may be encouraging you to confront your fears rather than avoid them. It might be beneficial to reflect on any current anxieties in your life and consider what you can do to face them directly. Seeking support from loved ones or addressing unresolved issues may help you find a sense of peace and clarity, allowing you to step out of the darkness and into the light.