Apparently it contains a (leaping) ski‐bishop, though no actual ski‐rook. Only one I could find though. EDIT: Never mind, apparently it's just an example. And all the other usages of ski‐sliders or Pickets (and their compounds) seem to be lame. Which leaves only a game which I've had in mind but not yet got round to writing up, where a leaping‐picket+wazir promotes from a Phoenix/Waffle. And arguably (albeit failing the ‘straight line’ condition) the original GA unicorn/rhinoceros
I must admit I'm surprised these aren't more popular…
The Google Custom Search turns up this when searching for ‘ski‐rook’: https://www.chessvariants.com/other.dir/abc-chess.html
Apparently it contains a (leaping) ski‐bishop, though no actual ski‐rook. Only one I could find though. EDIT: Never mind, apparently it's just an example. And all the other usages of ski‐sliders or Pickets (and their compounds) seem to be lame. Which leaves only a game which I've had in mind but not yet got round to writing up, where a leaping‐picket+wazir promotes from a Phoenix/Waffle. And arguably (albeit failing the ‘straight line’ condition) the original GA unicorn/rhinoceros
I must admit I'm surprised these aren't more popular…