I cannot provide a definitive answer to "Who is Rudy Pankow's old best friend?" because this information is not publicly available. Celebrities' personal relationships, especially those from their past, are often kept private. Unless Rudy Pankow himself has shared this information through an interview or social media, there's no reliable way to know.
Information about celebrities' friendships is often gleaned from:
- Social Media: Checking Pankow's social media accounts for mentions of close friends. However, this only reveals those he chooses to share publicly.
- Interviews: If he's discussed his friendships in interviews, transcripts or videos might be available online. However, this information might be limited and not specific to an "old best friend."
- Reliable News Sources: Reputable entertainment news outlets sometimes report on celebrities' close relationships, but this is unlikely for details as specific as an "old best friend."
Searching the internet will likely yield speculation and fan theories, but nothing concrete unless Pankow himself has revealed this information. Therefore, the identity of Rudy Pankow's old best friend remains unknown to the public.