ΔE 15.8, loose: different enough that you should pick on purpose. Snake Fang is a little lighter, much more saturated than Wraithbone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Snake Fang is a little lighter, much more saturated than Wraithbone.
The same difference applies the other way round: Wraithbone is a little darker, much more muted.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Wraithbone on the colour wheel See Snake Fang on the colour wheel
All matches: Wraithbone equivalents · Snake Fang equivalents