Thinker of the Zhou dynasty, traditionally the author of the 道德经 (Tao Te Ching) and founder of Taoist thought; Taoism later worshipped him as a god. Whether he really lived is debated.
Mind the tone: the philosopher is 老子, but 老子 with a neutral second syllable means 'father', and a man who calls himself that is being cocky, like 'your old man here': 老子不干了, 'I quit, damn it'.