pronoun
First-person plural pronoun used mainly by older men, especially in dialects such as Kansai or in fictional representations of elderly speakers. Carries a casual, sometimes rustic or self-deprecating tone.
わしらはもう年じゃけえ、若いもんに任せよう。
We're old now, so let's leave it to the young folks.
わしらも昔はよう遊んだもんじゃ。
We used to play a lot back in the day, too.
From わし (first-person pronoun used by older men) + plural suffix ら.