Dueling banjos is a period-24 oscillator found (in tetramer form, via apgsearch) by Apple Bottom on January 10, 2019. It consists of two B-heptominos being hassled by two eater 1s and two block on tables.

Matthias Merzenich provided a monomer form which has cis-in, cis-out and trans isomers depending on the relative positions of the two blocks.

Mark Niemiec posted a 19-glider synthesis of the oscillator on January 13th.