pò-bé-á報馬仔

informant

informant; informer; spy; someone who announces the procession of a deity; someone with a loose tongue

English Wiktionary, “報馬仔” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%A0%B1%E9%A6%AC%E4%BB%94 · confidence: Medium (Wiktionary)