THUMB ep 8
"Time Waits for No Frog"

Back to the Future: The Animated Series




7 (7 in series)


Cliff MacGillivray, John Loy & John Ludin


Phil Robinson


November 2, 1991

Episode chronology
Previous episode

"Go Fly a Kite"

Next episode

"Einstein's Adventure"

"Time Waits for No Frog" is the seventh episode of the first season of Back to the Future: The Animated Series, and the seventh episode overall. It first aired on November 2, 1991. "Einstein's Adventure" was aired along with the episode.

Brief synopsis[]

Doc and Marty go to Ancient Peru in the year 1532 to find a cure for Marty's athletes' foot. The cure comes in the form of an extinct frog — the Bufo Marinus — which emits an acid from its skin. Doc and Marty meet up with the vile conquistador Biffando de la Tanén and his goons. Biffando releases them and follows them at a distance, to the lost City of Gold. Marty and Doc end up being captured by Incan natives and are put in a large pit with hundreds of Bufo Marinus frogs. With that many frogs, Doc says that he and Marty will "melt like the Wicked Witch of the West." Using a tuning fork, Doc makes the frogs go crazy and it looks like Marty can "control" the frogs. The Incans release Doc and Marty and stop Biffando from stealing any gold. Doc and Marty take a couple of frogs home to reestablish the population in the 20th century. One of the frogs cured Marty's athlete foot.


(Doc, who has inadvertently made himself invisible, is talking on the phone with Marty)

Marty: "Doc, it's Marty, I gotta see you right away!"
Doc: "That would be a little difficult right now. Trust me on that one."
Doc: "Locating a Bufo marinus in the midst of this luxuriant foreign forest will be similar to discerning a sewing implement amidst a proliferation of hewn alfalfa."
Marty: "Or like trying to find a needle in haystack."
Doc: "That's what I said!"

(The Inca chief says that Marty will take the secrets of the Lost City to his grave)

Marty: "Whoa!! Are you talking death?"
Doc: "Fascinating! I've often wondered what the Incan methods of ritualized sacrifice were!"
Marty: "Yeah, I'm just dying to find out myself."

Marty: "Got it Doc! My feet feel better already!"

Doc: "Remember what happened to the Wicked Witch at the end of The Wizard of Oz?"
Marty: "Yeah."
Doc: "We won't be so lucky!!"
— {{{6}}}
Marty: "WHAT A WORLD!!!"
{{{3}}}: "{{{4}}}"
Marty: "{{{5}}}"
— {{{6}}}
Marty: "Oh not that conquistadork!"
{{{3}}}: "{{{4}}}"
Marty: "{{{5}}}"
— {{{6}}}


  • Bufo marinus is in fact, the Latin name for the cane toad, which is far from extinct.
  • This is the only episode of the series that is limited to Doc and Marty. Clara and the kids are not seen in this or in the other feature, Einstein's Adventure.
  • Doc tells Marty that he once went frog hunting with Mark Twain in Calaveras County, California. Mark Twain wrote his famous short story "The Celebrated Jumping Frog of Calaveras County" after visiting the county in 1865.
  • Doc makes a reference to The Wizard of Oz by mention of the Wicked Witch. Another reference is later made in "Retired".
  • This is the first episode where Marty's barefoot is seen. Despite that he had Athlete's Foot in this episode. The second time he will be seen barefoot wold be "Put on Your Thinking Caps, Kids! It's Time for Mr. Wisdom!"


By type
Characters Creatures Events Locations
Organizations and titles Vehicles Weapons and technology Miscellanea



  • Bufo marinis


  • South America (First appearance)
    • Peru (First appearance)
      • City of Gold (First appearance)

Weapons and technology

  • Tuning fork