Yes, it's considered very unlucky if a snake enters (or tries to enter) the house.
Particularly if it is a cobra.
It is believed it is bad spirits trying to enter.
Needs a monk or two to cleanse the house.
In my experience, at time of death here in Thailand, most overseas relatives will make excuses, and not bother getting on a plane.
Once you're dead they let the unfortunate Thai wife see you off.