Preheat oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper.
On a floured surface, roll out each tube of crescent dough into a large square about 1/4-inch thick. Place your hand or a hand shape cut out of paper onto the dough, and cut two hand shapes out of each tube of dough. Roll up the uncut dough, roll out again, and cut two more hand shapes (total of 8 shapes).
To assemble, lay four hand shapes onto the prepared baking sheet. Place two hot dog halves in a line, cut sides down, onto each finger and thumb. The hot dog halves should reach from 1/4 inch from the tip of each finger into the hand. Lay a second dough hand over the first one, covering the hot dogs, and pinch the two hand shapes together to enclose the hot dogs.
Bake in the preheated oven until the hands are golden brown, about 20 minutes. Allow to cool slightly; remove to a platter. Decorate the stumps of wrists with ketchup “blood” to serve.