رَأَيْتُ الْعَصَا وَغُلَامِي: I saw the stick and my servant.
وَ: conjunction.
غُلَامِي: coordinated with the accusative object الْعَصَا; therefore also accusative, with estimated fatḥa on mīm.
غُلَامِ: muḍāf; ي: possessive pronoun (muḍāf ilayh).
Why estimated? The visible kasra serves the attached first-person yāʾ, not the accusative case.