In a large bowl, stir together the sweetened condensed milk and vanilla extract. In a separate bowl, using a hand or stand mixer, beat the whipping cream on high until stiff peaks form (2 - 3 minutes).
Lighten the condensed milk mixture by stirring in about 1/2 cup of the whipped cream. Then stir in the rest of the whipped cream until well mixed. Fold in the crushed OREO cookies and halved maraschino cherries.
Scoop into a metal or glass loaf pan and smooth the top. Place a piece of waxed paper directly on top of the ice cream mixture to prevent ice crystals.
Place in the freezer for at least 6 hours or overnight. Once frozen, the ice cream will keep in the freezer for up to two weeks. Just be sure to keep the surface sealed with wax paper.
To serve, place a scoop of the ice cream on a plate and decorate with candy eyes, a maraschino cherry and pretzels.