Spell Binder is a mean wizard dressed in a white coat and turban who is an enemy of Letterman featured in the TV series The Electric Company voiced by Zero Mostel. He would express disgust at what was going on then use his trusty magic wand (stored beneath his turban) to change a key letter in the word (e.g., "custard" to "mustard").
Havoc would ensue as the result of Spell Binder's actions; for instance, in the above example, the people who were enjoying flavorful custard suddenly and unknowingly began eating red-hot mustard, causing them to turn red and burn from the mouth. Spell Binder would then revel in his fun.
After the narrator expresses despair at the situation, the heroic Letterman—having observed the situation from afar—jumps into action. He replaces the incorrect letter with a more appropriate one that was conveniently placed on his varsity sweater (e.g., "Ripping a 'c' from his varsity sweater ..."), after which time the situation was resolved and things went back to normal. Spell Binder expressed disgust and frustration that Letterman once again foiled his fun ("Curses" or some similar line), while Letterman was sometimes invited to join with the people he helped in whatever they were doing.
Though nearly all episodes of the segment were stand-alone stories that followed the same general story line, there were some exceptions. One episode functioned as an origin story, portraying Letterman's childhood and growing up. The most notable episodes were the ones where Letterman himself, rather than some innocent victim(s), was the target of Spellbinder's torment. Examples were:
- "Betterman"- Spellbinder changes the "L" in "Letterman" to a "w" ("wetterman"), causing Letterman to struggle in a pool to keep from drowning. Letterman is somehow able to find a "b" and replace the "w" to make "Betterman" ("better man than he was before.")
- In one episode, Letterman declares he feels "good". Spellbinder changes the "g" to a "w" for "wood", turning Letterman into a talking tree. Spellbinder then proceeds to get a drill to try to drill holes in Letterman. Before Spellbinder returns, Letterman is able to convince a small bird to take a "g" from his front and replace the "w", thereby turning him back into the "feeling-good" Letterman, just in time as Spellbinder attempts to drill into him. The drill breaks and engulfs Spellbinder in the twisted metal.
- In another, the narrator declares Letterman good as "gold". Spellbinder removes the "g", leaving "old" and turning Letterman into an aged version of himself. Letterman summons what little strength he has and takes a "b" from his sweater to make "bold", restoring him to his youthful condition.
- "Small Talk (2 parts)"- Spell Binder sneaks into Letterman's home in order to exact revenge for being foiled, time and time again. He spies upon Letterman, who happens to be packing away all of his letters into a trunk as he prepares to go on vacation. Spell Binder changes the "trunk" into "junk," then proceeds to shrink Letterman down to six inches tall by changing "junk" into "shrunk." However, Letterman then changes "shrunk" into "hunk," which restores his college-football-player physique. He then proceeds to bend Spell Binder's wand, rendering it useless, setting Spell Binder to breaking down and crying. In the second part ("A Friend In Need"), a re-composed Spell Binder has been placed behind bars. The narrator of the episode declares, "This looks like the end of a fiend," which inspires Spell Binder to use his bent wand as a letter "r" to change "fiend" into "friend." A strange-looking monster appears and the narrator exclaims, "I didn't know he had any friends!" to which Spell Binder answers back: "We went to school together." The monster bends the bars of Spell Binder's prison cell, allowing him to slip out and escape.