A defiant Mamata Banerjee invoked the spirit of the Royal Bengal Tiger on Tuesday, as she and BJP chief JP Nadda traded barbs while on the campaign trail ahead of the Assembly election. "I am not weak. I am strong. I will walk with my head held high till the time I am alive. I will live like a Royal Bengal Tiger till the time I live," Ms Banerjee roared, even as senior leaders - the most recent of whom was former Forest Minister Rajib Banerjee - quit and join the BJP.