4. Brucie Kibbutz
In GTA IV, Kibbutz obsessively expounded the virtues of steroids, and in particular of using Bullshark Testosterone as a supplement to work-outs - to the extent that almost every meeting with him seemed like an advert for getting juiced. With Bullshark Testosterone back in GTA V, which you can hear in a Weazel News report about its effects, it was only right that Brucie would appear, and he is mentioned in that same report as the spokesman for the company. There's also a website for the product, which carries an image of a slightly ages Kibbutz, and it's possible to read his bleets on Bleeter (there are a lot of them during the story.) Brucie also appears in the GTA Online portion of the game: he contacts the character after you hit rank 17 to say he will order Bullshark testosterone, which the player can then have access to, doubling damage dealt and cutting damage taken by half for a short period.
How To Find Him You can either find the website online by searching for Bullshark Testosterone, or find Kibbutz on Bleeter, if you don't want to level up to rank 17 in Online for a chance to actually get your hands on the product.