You are likely thinking of L, the brilliant detective who is the main antagonist to Light Yagami.
L is a reclusive, eccentric detective known for his incredible deductive skills and ability to solve even the most complex crimes. He is tasked with catching the mysterious killer known as Kira, who is using the Death Note to kill criminals.
While L is known for his unique mannerisms, such as his love of sweets and his slouched posture, he is a highly intelligent and strategic individual who poses a significant threat to Light.
It's possible you're thinking of an alternate spelling or a fan-made character.