Place milk, sugar, and tapioca pearls in a slow cooker.

Stir well to combine.

Cover and cook on high for 2 to 5 hours, until tapioca is soft.

In a separate bowl, whisk eggs and vanilla extract together.

Measure out 1/2 cup of the hot milk and tapioca mixture.

Whisk the hot mixture into the egg mixture.

Repeat the process, adding two more 1/2 cup portions of the hot mixture to the egg mixture while whisking.

Pour the egg and tapioca mixture back into the slow cooker.

Whisk until thoroughly combined.

Cover and cook on high for 30 to 45 minutes, or until the pudding thickens.

Unplug the slow cooker and let the pudding cool for about 1 hour.

Ladle into serving bowls and chill in the refrigerator before serving.