Hey there!
So depending on what you've done so far, you might not have the time. Each of the three starting transformations has different options based on where you talk to them. For the Bull, you need to talk to Damien 3 times at the shake shack when he's there (Avoid talking to him in the gym. You can unlock both options in the same play through as selectable, but you can only talk to them in one place a day)
After 3 conversations, visit Mason in R&D, talk to him about Damien, and choose the protein shakes.
More info if you need it! https://sinspirational.com/paradise/walkthrough.html