Tomorrow's schedule will be filled with lots of marathons, football and specials, and the New Year ushers in all sorts of new series. This, therefore, is unofficially not only the last stultifyingly boring TV night of 1994, but one of the last such evenings for quite a while into 1995. Maybe even for an entire week.
* "The X-Files" (9 p.m.-10 p.m., Channel 45) -- This underground TV hit goes underground itself, in a repeat episode about a creepy and giant parasite living in the sewers beneath the streets. Very clever special-effects work, and some good
photography, combine to make this an effectively creepy "X-Files" -- a sort of earthbound version of "Alien." (And watch out for those "le sewer" peas.) Fox.
* "BSO: Beyond Baltimore" (10 p.m.-11 p.m., Channel 11) -- WBAL again runs its intriguing look behind the scenes at the Baltimore Symphony Orchestra's tour of Asia this fall. Besides capturing the musicians' passion for their art, the show depicts some quirky moments not to be missed, including a tour of a Japanese convenience store.
* "Monty Python and the Holy Grail" (10 p.m.-midnight, COM) -- Monty Python fans, consider this a Major VCR Alert. Terry Jones and Terry Gilliam offer running commentary (well, talking commentary, anyway) during this special showing of their 1975 King Arthur comedy. You'll learn, among other things, how they used cardboard cutouts for castles, which scenes they thought worked the best, and whose work got left on the cutting-room floor. All in all, it's something completely different.
* "Thunderbirds Are Go" (12:45 a.m.-2:45 a.m., TNT) -- Actually, Thunderbirds are frightening. These marionette heroes, in the '60s, were the creepiest low-budget creations this side of "Clutch Cargo." What's worse than a "Thunderbirds" movie?
* "Thunderbird 6" (2:45 a.m.-4:40 a.m., TNT) -- . . . Two "Thunderbirds" movies.