This tutorial demonstrates how to create a spooky phone call using Twilio Voice and Amazon Polly. The process involves creating an audio file with a scary message, adding effects to it using ffmpeg, uploading it to an Amazon S3 bucket, and then playing it over the phone using Twilio Voice. The tutorial covers setting up AWS IAM credentials, creating an S3 bucket, preparing the audio message with Amazon Polly, adding effects to it using ffmpeg, and finally making a phone call using Twilio Voice. The code examples are provided for each step of the process, and the tutorial is suitable for developers who want to create a fun project or experiment with cloud services such as AWS and Twilio.