"Mam wesołego wujka."

Translation: I have a cheerful uncle.

[rvabbott]

Uncle is the direct object here. I take it mam takes the genitive?

[immery]

accusative. Wujek is masculine animated so accusative=genitive

[idanlipin]

The voice says wujka as 'wujika'

[Crimthann__]

Nazywany jest Romek, ma na przedmieściach domek