from an empirical point of view, Neither is credible. From other points of view?
Witnesses:
God - Most eyewitness testimony is too old to be useful
Bigfoot - most eyewitness testimony is from dubious sources
physical proof:
God - Only his handiwork, which is not recognized as such by many
Bigfoot - abundant footprints, hair, and photographic evidence. Much of which has been debunked, which casts doubt on the rest.
God does have one advantage in this debate however. Many scientists disbelieve the Bigfoot thing because they find it unlikely that a large humanoid could live for so long with humans nearby without ever leaving a body. God doesn't have this disadvantage. He is supposed to be elusive by nature. His absence is much more explainable.
So, I'll give the credibility to God. I must add the caveat that sasquatch is much more scientifically provable.