What are the three superstitions that Tom follows in the novel?

Tom and Huck go into the graveyard with the dead cat at midnight. It is supposed to take away warts.

Another superstition is that murdered bodies will bleed in the presence of their murderers.

In addition, the pact signed in blood is believed to be a binding agreement. If you break it, you die. Tom and Huck sign one to promise that they won't reveal who murdered Doc.