I thought it had an Eastern European look, but I hadn't spotted the lower wing. That and the bracing strut triggered a vague memory.
There's ugly and then there's the PZL-M15 Belphegor:
Several claims to fame according to Wikipedia:
The PZL M-15 is believed to be the world's only jet agricultural aircraft (i.e. the world's only jet crop-duster), the world's only jet biplane and the world's slowest jet
The name is a nickname:
In demonology, Belphegor is a demon, and one of the seven princes of Hell, who helps people make discoveries. He seduces people by suggesting to them ingenious inventions that will make them rich.