Dyeing for Your Art: Lloyd's chipped tooth is real - Jim Carrey had chipped his years previously, and had it uncapped for this film.
Jeff Daniels also got his hair naturally frizzy that way by not conditioning, blow drying, or combing his hair for two months.
Hey, It's That Guy!: Nicholas Andre was played by former Saturday Night Live cast member Charles Rocket (from the 1980-1981 season, which was considered one of SNL's many low points). What's funny is that Jim Carrey auditioned to be on the 1980-1981 season and was passed up in favor of Rocket.
One Steve Limit: Averted out-of-universe; actress Karen Duffy oddly played two characters named Shay that year, in this film and Blank Check.
Averted also with Jeff Daniels, who played two characters named Harry in 1994, the other being in Speed.
Romance on the Set: Jim Carrey and Lauren Holly married after meeting on this film, but it lasted less than a year.
Throw It In: Jim Carrey threw in quite a bit, like "We landed on the moon!" and even "the most annoying sound in the world" (with the latter, you can clearly see Jeff Daniels and Mike Starr trying to hold it together, bracing for whatever Carrey was about to do; Daniels fails and loses his shit right before it cuts to a close-up of Starr).