Transpo Tricks

Transposing from one opening to another can be a useful trick. If you suspect your opponent has prepared for line A, and you manage to sucker them into Line B can be unsettling, both because they haven't prepared for Line B, and the fact they know you've put one over them.
Normally such transpositions happen 'inside' the opening, where you simply shift variations via a different move order. However I've seen some weirder examples (Where a game starting with 1.Nc3 ended up as a Schliemann Ruy Lopez via a Lativian Gambit and where the move Bb5 came at the very end of the transposition).
In the following casual game, it started off as an Alekhines Defence, which was met with 2.Nc3, and ended up as a Blackmar-Diemer, after my opponent avoided a transposition into a Vienna.

1.e4 Nf6 2.Nc3 d5 3.d4 dxe4 4.f3 exf3 5.Qxf3 c6 6.Be3 Bg4 7.Qf2 e6 8.Bc4 Bb4 9.Nge2 Bxe2 10.Qxe2 Ne4 11.0-0 Nxc3 12.bxc3 Bxc3 (D)
13.Rxf7!! Bxd4 [ 13...Kxf7 14.Rf1+ Ke8 15.Qh5+ g6 16.Qe5+-;
13...Bxa1 14.Bxe6 leads to a winning attack.] 14.Raf1 Bxe3+ 15.Qxe3 Qb6 16.Qxb6 axb6 17.Bxe6 Ra5 18.Rxb7 Na6 19.Rff7 Nc5 20.Rb8# 1-0