Jeffrey Combs (who plays semi-regular Andorian Commander Shran in other episodes) plays the Ferengi Krem. This is the 2nd Star Trek series where Combs has played a Ferengi character. Combs also played the recurring character of FCA (Ferengi Commerce Authority) Liquidator Brunt in Star Trek: Deep Space Nine (1993).
The Ferengi never reveal their species name (at least not on camera). In fact, Ethan Phillips' character even says "Who we are is not important." This is likely to keep the continuity of canon as the Ferengi are supposedly not seen in the flesh by any Starfleet member until the first season of Star Trek: The Next Generation (1987).
The Ferengi Muk asks "Do I look like a Menk to you?" The Menk were the lesser evolved species of the planet Valakia (the Valakians being the dominant species) seen in Star Trek: Enterprise: Dear Doctor (2002). In that same episode, the Valakians mention the Ferengi, but no one on Enterprise has ever heard of them.
Many Star Trek fans did not agree with the presence of the Ferengi in this episode. They stated that first contact with them occurred almost 200 years later in Star Trek: The Next Generation: The Last Outpost (1987), so the Ferengi didn't belong in the 'Enterprise' era. However, this encounter does not qualify as an officially recorded first contact, since the Enterprise crew never learns their species' name. Furthermore, it has been established in Star Trek: The Next Generation: Encounter at Farpoint (1987) that humans knew of the Ferengi by reputation long before the official first contact; Captain Picard had even fought with them nine years before 'The Last Outpost', but he never had visual contact with them. So it isn't too far-fetched that there were more brief skirmishes with the Ferengi over the centuries prior to first contact.
Being without his own uniform, Tucker borrows a junior science officer's uniform and wears it throughout the episode. Tucker is the only crew member to wear all three division color versions of the Starfleet uniform in the series as he later wears the gold, command division uniform in Star Trek: Enterprise: Twilight (2003).
On the Ferengi ship, one of them is holding a whip. This can shoot out an electric charge and is the weapon of the Ferengi. This can be seen be seen when the crew of the Enterprise-D first run into the Ferengi in Star Trek: The Next Generation: The Last Outpost (1987). Surprisingly, the energy whips only appear on screen in the Ferengi's very first and last appearances, and were never on Star Trek: Deep Space Nine (1993), the show where the Ferengi were most prominently featured.
This episode states that the sixth Rule of Acquisition is "Never let family get in the way of profit." By the 24th century, it will have changed (slightly) to "Never let family get in the way of opportunity," as is revealed in Star Trek: Deep Space Nine: The Nagus (1993).
Jeffery Combs has the distinction of portraying eight different characters on Star Trek series. He has played the roles of Brunt, Weyoun, Shran, Tiron, Kevin Mulkahey, Penk, Krem, and a holosuite guest. He is one of only five actors to play seven or more different characters in the Star Trek franchise, the others being Randy Oglesby, J.G. Hertzler, Vaughn Armstrong and Thomas Kopache. Combs has appeared on Star Trek with all four of those actors.