The Amazing Mumford is a talented magician, but his magic tricks sometimes go awry. His characteristic magic words are "A la peanut butter sandwiches!" After saying this and waving his wand, there is a puff of smoke usually accompanied by either a "poof" noise or magical tinkling sounds, and then after clearing, it reveals how the trick has gone wrong.
Grover often appears as Mumford's over-eager assistant.
- Mumford's voice is based on that of the famous comedian W. C. Fields.
- The CTW archives' program summaries for Episode 0305 and Episode 0322 refer to Mumford as "the Amazing Ralph."
- In some of Mumford's scenes in the direct-to-video special A Magical Halloween Adventure, the character was performed on-set by John Kennedy with dialogue looped later by Jerry Nelson. However, one brief bit of dialogue remains unlooped in the final product: a scene in which Mumford speaks on the phone with his friend Gilda the Great.
- On Sesamstrasse, the German co-production, Mumford is named "Mumpitz", which means nonsense or balderdash.
- According to The Sesame Street Bedtime Storybook, Mumford lives in a castle, next door to the castle owned by Count von Count.
|Image||Earliest Known Appearance||Description|
|Episode 0280|| Disappearing Pineapple Trick|
The Amazing Mumford begins his magic subtraction trick with four pineapples, and makes them disappear one at a time. Then Grover makes Mumford disappear.
The story was retold in the book The Amazing Mumford and His Amazing Subtracting Trick.
|Episode 0311|| Raising and Lowering Trick|
The Amazing Mumford performs his "Up and Down Trick" by raising and lowering Grover.
|Episode 0322|| Full and Empty Cookie Jar|
The Amazing Mumford waves his magic wand over a transparent glass cookie jar and makes the jar become full of cookies and then empty (over and over) as an anxious Cookie Monster watches.
|Episode 0332|| Suspension Act|
Grover volunteers to assist Mumford in his suspension act. Grover will get on top of a platform, and Mumford will pull the pillar off from underneath, and the platform will not fall. The trick works, so Grover decides to try it himself, with Herry Monster as his assistant. Grover can't pull it off, and Herry falls.
|Episode 0381|| Surprise|
A woman volunteers to assist The Amazing Mumford in his surprise magic trick. Mumford makes her disappear – but when he tries to make her reappear, Herry Monster pops up, saying "SURPRISE!" (Note: In this trick Mumford uses the magic words "peanut butter" by themselves, instead of his longer trademark phrase.)
|Episode 0712|| Rabbit Trick|
Grover watches Mumford practice a trick, making a rabbit come out of his hat. Mumford has trouble getting a rabbit to come out of the hat; both are oblivious to the fact that Grover gradually turns into a rabbit.
|Episode 0725|| Rhyming Trick|
Grover volunteers to assist Mumford in his rhyming magic trick, making three things come out of his hat that rhyme with "knee". Grover guesses the first one (key), but doesn't get the last two (ski and tree) right.
|Episode 1075|| MAGIC|
The Amazing Mumford sounds out the word MAGIC, then makes himself disappear.
|Episode 2407|| Rabbit Out of a Hat|
Mumford is in the courtyard trying his darnedest to pull a rabbit from his hat without any luck. In fact, he's never been able to achieve the feat. Along happens Professor D. Rabbit who agrees to help him out so long as the two may reverse roles afterward.
|Episode 2579|| Gladys the Cow Disappears|
Gladys the Cow assists the Amazing Mumford on stage. Mumford says he will make her disappear, but his attempts fail, so he says he'll turn her into a duck instead. She runs off the stage in fright, which means his trick did work this time.
|Episode 2840|| Disappearing Carrot|
Grover is about to eat his carrot when he hears Mumford approaching. Grover asks Mumford to make the carrot disappear. Mumford obliges...by eating the carrot.
|Episode 3168|| Big and Small Trick|
A Sesame Street News Flash, in which Kermit the Frog interviews Mumford, who is showcasing his big and little trick, where he will make Thumbelina big and The Big Bad Wolf small. He succeeds in making Thumbelina big, but makes Kermit (not the Big Bad Wolf) small.
|Episode 3869|| Hungry Baby Bear|
The Amazing Mumford approaches a sad Baby Bear, who still can't find any porridge, and misses Telly. Mumford offers to make him a porridge bowl with magic, but his spell literally turns Baby Bear into one!
|Episode 4004|| Letter of the Day: C|
Cookie Monster asks The Amazing Mumford to make the cookie with the letter of the day disappear so that he can't eat it. Mumford tries and fails to make the cookie disappear, but Cookie Monster figures out a way to do it...
|Episode 4107|| Little Big Bird|
Mumford accidentally shrinks Big Bird down to the size of a ladybug. In the next episode, fortunately, he meets Mike the Ladybug, who helps Big Bird travel down the street, trying to get to Gordon and Alan. At last, Mumford accidentally restores Big Bird to normal size.
|Episode 4270|| Lette "R" Mystery|
This is Jerry Nelson's last performance as The Amazing Mumford before the performer's death in 2012.
| The Leslie Mostly Show|
Leslie Mostly interviews Mumford at his home. He tries to conjure up a rabbit for her, but ends up turning himself into a rabbit. When Mumford attempts to become a person again, he succeeds...and accidentally turns Leslie into a rabbit.
- Sesame Street
- Sesame Street Presents: Follow That Bird
- The Muppets: A Celebration of 30 Years
- Sesame Street: 20 and Still Counting
- Sesame Street Jam: A Musical Celebration
- Sesame Street: 25 Wonderful Years
- Imagine That
- Don't Forget to Watch the Movie
- Cinder Elmo
- A Magical Halloween Adventure
- A Celebration of Me, Grover
- The Amazing Mumford and His Amazing Subtracting Trick (1972)
- More Sesame Street Finger Puppets (1972)
- The Sesame Street ABC Storybook (1974)
- Big Bird's Busy Book (1975)
- See No Evil, Hear No Evil, Smell No Evil (1975)
- The Sesame Street A to Z Coloring Book (1976)
- The Sesame Street Block Party Coloring Book (1977)
- The Sesame Street Mix or Match Storybook (1977)
- Who's Who on Sesame Street (1977)
- The Sesame Street Bedtime Storybook (1978)
- The Sesame Street Cookbook (1978)
- The Amazing Mumford Forgets the Magic Words! (1979)
- The Amazing Mumford Presents All About Bones (1980)
- The Count Counts a Party (1980)
- The Sesame Street Dictionary (1980)
- The Amazing Mumford Presents the Magic Weather Show (1981)
- I Have a Friend (1981)
- Prairie Dawn's Upside-Down Poem (1981)
- Put & Play Magic Show (1981)
- The Sesame Street Sun (1981)
- Which One Doesn't Belong? (1981)
- Big and Little Stories (1982)
- More Who's Who on Sesame Street (1982)
- A Sesame Street Christmas (1982)
- The Sesame Street Word Book (1983)
- There's No Place Like Home (1983)
- Trace & Color Alphabet (1984)
- Big Bird's Book of Rhymes (1985)
- I Can Count to Ten and Back Again (1985)
- ABC (1986)
- A My Name Is Annabel (1986)
- Sesame Street ABC (1986)
- Colors (1987)
- A My Name Is Alice (1989)
- Happy and Sad, Grouchy and Glad (1992)
- Imagine... A Million Kittens for Elmo (1993)
- Knock, Knock! Who's There? (1994)
- B is for Books! (1996)
- Elmo's Tricky Tongue Twisters (1998)
- The Counting Carnival (2003)
- Abby Cadabby's Rhyme Time (2007)
- Color Carnival (2008)