Which Maya ruler was known as '18 Rabbit'?

The Maya ruler known as “18 Rabbit” was Uaxaclajuun Ub'aah K'awiil, the 13th ajaw of Copán in present-day Honduras.

He ruled from about 695 to 738 CE during Copán’s Classic-period peak. His name is also rendered as Waxaklajuun Ub'aah K'awiil; the Maya name refers to “18 images” or “18 are the faces” of K'awiil, a deity associated with power, lightning, and rulership. “18 Rabbit” is a modern English rendering of the ruler’s name glyphs, not a separate personal nickname in the modern sense.

Uaxaclajuun Ub'aah K'awiil is strongly associated with Copán’s monumental art, including elaborate stelae and the famous Hieroglyphic Stairway. His reign ended dramatically in 738, when he was defeated and captured by K'ak' Tiliw Chan Yopaat, the ruler of Quiriguá, a former subordinate polity. He was subsequently executed, a major political shock for Copán.

The main mix-up is with K'inich Yax K'uk' Mo', founder of Copán’s ruling dynasty, and Jasaw Chan K'awiil, a ruler of Tikal. Neither is identified as 18 Rabbit.