Canon Foreigner: He only appears in the 1999 series. He was added in because with Hilda and Zelda as teenagers, there was no adult guardian living in the house.
Chuck Cunningham Syndrome: He disappears in Sabrina's Secret Life with no explanation. However, one could guess that he left because by then, Hilda and Zelda were legally adults at that point, and didn't serve a purpose anymore.
Cute Bruiser: In "Hexcalibur", during the fight with Morgana, as Merlin. He makes the Badass Boast "If you mess with my best friend, I'll turn into a huge dragon and then you'll be sorry."
Epic Fail: In "Hexcalibur", as Merlin he was absolutely useless at any form of magic that didn't involve dropping an anvil on someone or himself. "Paranormal Pi", Get's pulled through the air by a magic detector, mistakes a chair for a UFO get's thrown in the mud by aforementioned magic tracker and is the laughing stock of the whole town. Also, let's not forget this little exchange from picture perfect. Sabrina *about the school assembly* "the joys of stamp collecting?" Pi- *with a stamp* "stamp collecting, really? Now that is righteous." *gets stared at* "what? You disagree?"
Genius Ditz: Sabrina even described him as "totally smart and really out of it at the same time".
Manipulative Bastard: Not in the evil sense, but he pretty much pulls this on Harvey in "Nothin' Says Lovin' Like Something from a Coven" to get Harvey to pull a break-in and scare type Halloween prank with him. (Although this can be pretty scary if you consider he might be doing this off-screen and what he could smooth talk Harvey into doing, although this is Pi we're talking about.)
Trickster Mentor: He comes off as evil and scary but always left a loophole in whatever Sabrina wished for so she could find a way to fix it when it (inevitably) goes wrong. Though he's tired of constantly being asked.