This is a cartoon involving shadows coming to life and committing petty theft. Now that I've spoiled that for you, I can list all of the titles that they could have used for this rather than "The Dark Terrors":
Ok the last three were of my own creation and terrible. Therefore I'm stopping. On with the sh(ad)ow.
Spider-Man is swinging around town on a hot Sunday afternoon. The street are empty as they heat is keeping most New Yorkers inside [Good justification for not drawing any crowds!].
Suddenly he hears a woman's scream. Following the sound he finds that it's Betty Brant. She's cornered by the shadow of a tiger. Not a tiger; it's shadow. While trying to protect her, he is batted aside by the curiously animated shadow. Spider-Man isn't quite sure what just happened, but he knows that whatever it was, it was real.
At the Daily Bugle [I assume the next day], Betty tries to explain to Jonah (and Peter) about her encounter with the shadow. Jonah of course doesn't believe such nonsense. He doesn't believe it until strangers begin calling in reporting more of the same thing.
Peter leaves and changes to Spider-Man. He begins looking around for clues to explain the sudden independent and aggressive stance that shadows have taken. He is unaware he is being monitored by the The Phantom. He has created "Shadow Scope" glasses that emits a dual beam that converts shadow puppets into three-dimensional objects and projects them anywhere in the city [Hey, Phantom. Joe "A Guy Named Joe" Smith (Amazing Spider-Man (Vol. 1) #38) called. Wants to hand over his "Lamest Villain" award to you.]
Intent upon humiliating Spider-Man, he creates a shadow puppet of a boxer [Out of one finger if you can imagine that. No, not that finger.] to teach him a lesson. The boxer proves to be too much for the web-slinger and after receiving a few well-placed punches, contorts like a Rock 'Em Sock 'Em robot and falls down. He then sends the shadow of a cobra to rob a jewelry store.
Seeing that Spider-Man is still in pursuit, The Phantom sends a shadow of an Sherman Tank after him [Didn't think I could identify that, did you?]. Spider-Man attempts to elude the tank by climbing to the roof of a building, but the tank follows [Must be using the same logic they did in Batman Forever]. Taking a desperate gamble, he turns a small pocket flashlight on the shadow, dispersing the darkness. [Maybe he should have made the shadow of a banana and shoved it in the exhaust port?]
For the next shadow assault, it's a gorilla robbing a jewelry store. Instead of attacking it, Spider-Man follows it back to The Phantom's hideout. When Spider-Man announces his presence [which never has the intended result of immediate surrender] The Phantom uses his Viewmaster© goggles to create more underlings, which are easily overpowered. The Phantom then concentrates the energy visor into an intense heat ray in an effort to incinerate Spider-Man. Spider-Man is able to eventually separate The Phantom from his goggles and turn him over to the police.
The Phantom has some serious engineering skills, I'll give him that. However I also give him an additional award: the not-so-coveted "Biggest Waste of Talent".
The writers got to a lot of trouble making The Phantom capable of creating whatever technological marvel he wants. Unfortunately this is done in uninteresting ways and comes across as an annoyance similar to his Z-List comic counterparts Mindworm, Mirage, Kangaroo, Humbug, etc.
1 web. Animating shadows to commit crimes is a great idea until you start thinking about it. Their intangibility shouldn't allow them to carry anything. Also the Shadow Scope glasses shouldn't be able to project a 3-D shadow to the location being viewed through a monitor. Granted that's asking a bit much from a kid's TV show, but this is one of the many flaws in this episode.