A helpmate with promotion from one side in the set play and from another in the actual play.
See also: Promotion.
Kniest, Peter
Deutsche Märchenschachzeitung, 1932
1...f4
2.Sf3
f5
3.Se5
f6
4.Sf7
fxg7
5.Sh8
gxh8=Q#
1.Sxe2
Kxe2
2.d1=R
f4
3.Rd8
Kf3
4.Rh8
Kg4
5.Rh7
fxg5#