Are you sure:
- Are you sure Gligar is holding the razor fang?
- Are you sure your ds's time is set correctly
- Are you sure Gligar is not holding another item like the razor claw?
The time may not be set to night time. Try setting it to night time in the ds settings.
Also, Gligar may be holding the razor claw instead of the razor fang.
I hope this was helpful!