Preheat oven to 325˚F (160˚C) and line two large baking sheets with parchment or lightly grease.
In a large bowl, beat together the butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the eggs, one at a time, followed by the vanilla extract.
In a medium bowl, whisk together flour, baking soda, and salt.
Mix the flour mixture into the butter mixture until just combined with no streaks of flour. Fold in 9 ounces (255 grams) of the chocolate chips.
Use a medium scoop or large spoon to scoop balls of dough onto prepared baking sheet, 2 1/2 to 3 inches (6-8 centimeters) apart.
Press 3-5 chocolate chips, base side up, into the top of each ball. Bake in preheated oven until the edges are set and lightly golden, 14-18 minutes.
Allow to cool on baking sheet for 5 minutes before removing to wire rack. Repeat with remaining dough.
Once the cookies are completely cool, place remaining chocolate chips in a small bowl. Microwave at 20 second intervals, stirring in between, until smooth. Transfer to a pastry bag fitted with a small round tip or a quart sized ziploc bag with a small corner snipped off.
Pipe 4 legs on each side of the exposed chocolate chip bases. Allow to set on counter (or in refrigerator if hot in the kitchen).
Store in airtight container at room temperature for up to 3 days.