pronoun
Archaic humble first-person pronoun used by men. In modern Japanese, it is only encountered in historical contexts, period dramas, or deliberately old-fashioned speech.
「やつがれはただの旅の者にござる」と侍が言った。
"I am but a mere traveler," said the samurai.
Common informal male first-person pronoun; やつがれ is an archaic reading of the same kanji with a humble nuance.
The historical derivation is uncertain. The kanji 僕 originally meant 'servant' or 'manservant', and the reading やつがれ likely developed as a humble self-reference.