The individuals who may be considered the biggest "克星 (kè xīng)，" or nemesis， for those born in the Year of the Rabbit are:

Rooster (鸡/雞): The Rooster and Rabbit clash， creating friction and hindering the Rabbit's fortune. The Rooster's critical and fault-finding nature can undermine the Rabbit's confidence.

Rat (鼠): Rabbits should be wary of those born in the Year of the Rat， as Rats may take advantage of the Rabbit's gentle nature for their own gain. Disharmony may arise from constant calculation and disputes.

Dragon (龙/龍): The Dragon's domineering nature and need for control can clash with the Rabbit's desire for peace and harmony. The Dragon's ambitious spirit may also clash with the Rabbit's more laid-back attitude， creating pressure and a sense of inadequacy for the Rabbit.

Horse (马/馬): The clashing personalities of the Rabbit and the Horse can lead to frequent arguments. Their conflicting natures may cause them to dislike each other， leading to open and hidden disputes， making harmonious relationships unlikely.