1. A Filipino myth tells that an abundant amount of tiny crabs (pakot) and tiny shrimps (alamang) in the rivers foretell typhoon.
2. When a pregnant mother craved for crab, the baby will be born with crab-like fingers.
Source:
A Handbook of Philippine Folklore, By Mellie Leandicho Lopez, pg. 1 and 2
Crabs Folklore 