Cebulman 

An individual of Eastern-European origin, who emigrated to the UK and, following a significant improvement to their status, career, and finances, behaves like an obnoxious twat.

Etymology:
Cebula - (pl.) Onion
Man - (eng.) A representative of homo sapiens species.

Look at that cebulman.
He's such a cebulman.
He comes from Śląsk, no surprise he's such a cebulman.

Cebulman by Duracellie June 9, 2020