  We point out a potential common origin of the recently observed 750 GeV
diphoton resonance and a Weakly Interacting Massive Particle (WIMP) candidate.
In a dark QCD sector with an unbroken dark G-parity, the diphoton resonance
could be a dark G-even pion, while the WIMP could be the lightest dark G-odd
pion. Both particles are Standard Model gauge singlets and have the same decay
constant. For the dark pion decay constant of around 500 GeV, both the diphoton
excess at the LHC and the dark matter thermal abundance can be accommodated in
our model. Our model predicts additional dark G-even and dark G-odd color-octet
pions within reach of the 13 TeV LHC runs. For the 5 + 5bar model, compatible
with the Grand Unified Theories, the WIMP mass is predicted to be within (613,
750) GeV.
