やろうか

shall I ... for you?

→ 遣る
phrase Uncommon #16,579
shall I ... for you? Usually follows a て-form, as in 開けてやろうか. It is a rough or masculine way to offer to do something, and can sound condescending depending on context.
JA: 荷物を持ってやろうか?
EN: Shall I carry your bags for you?

おいジョーそいつを撃ってやろうか

Hey, Joe, should I shoot him?

— レザボア・ドッグス (1992)

一発殴ってやろうか

Want me to punch you?

— きっと、うまくいく (2009)

俺も殴ってやろうか

Do you want me to hit him too?

— ブエノスアイレス (1997)

かけてやろうか

Want me to call them for you?

— レザボア・ドッグス (1992)

言ってやろうか

Want me to tell them?

— コーカサスの虜 (1996)

教えてやろうか

Want me to tell you?

— ライフ・イズ・ビューティフル (1997)

開けてやろうか

Want me to open it for you?

— レオン (1994)