If you don't use the clean or empty Nightlife template, the Tricous are an Easter Egg downtown. There are several downtownie sims who each know one or two of the family. By getting the correct teen townie sims to move into your family, thus making them playable (keeping in mind that NL was before we could grow them up using the FT birthday option) and if you get a resurrection phone, the various downtownie teens are the key to resurrecting the family.

I remember once seeing a tutorial on resurrecting all the Tricous. Might have been a link to an Exchange story, maybe? Either way, someone made a list of which teen to move in first, who they can resurrect, etc etc in order. Because not all the Tricous know one another. But if you move in the correct teens and if resurrect the dead sims in the correct order, you can resurrect the whole clan.

Or you can just use Mixreality's Downtown template and have them as a Downtown bin family :)