Han-era tomb finds include bronze
虎子 (hǔzi, 'tiger pots') — tiger-shaped urinals, the ancestor of
便壶. The tiger shape was reportedly dropped during the Tang dynasty because Emperor Gaozu's grandfather was named
李虎 (Lǐ Hǔ, 'Li Tiger'); using his name on a chamber pot was deemed disrespectful, so the design changed and the name shifted to
马子 (mǎzi) and later
便壶.
