Who is the only eunuch buried in the imperial tomb in the history of eunuchs?

The only eunuch buried in the imperial tomb in history was Wang Chengen, who was trusted by Emperor Chongzhen of the Ming Dynasty.

In March of the seventeenth year of Chongzhen, Li Zicheng captured the capital. 19, Zhu Youjian and his personal eunuch Wang Chengen boarded Jingshan Park and hanged themselves in Shouhuang Pavilion. Wang Chengen Zhong Jun Zhu Shi also hanged himself in Jingshan Park. Three days later, Li Zicheng found the body of Chongzhen. On April 4th, Li Zicheng buried Chongzhen near the Ming Tombs, which was later called Siling. Wang Chengen was buried in the cemetery in front of Siling, which was later called Wang Chengen's Tomb.