The Blob from the 1958 film vs. the real blob: science vs. fiction

Ever heard of the 1958 film The Blob starring Steve McQueen? That gelatinous extraterrestrial creature devouring a small American town? Well, our Physarum polycephalum has almost nothing to do with it—but that is where it gets its nickname. A pop culture and science breakdown.

🎬Photo: side-by-side montage of the 1958 film poster and a macro photo of a plasmodium

Why is the blob called a "blob"?

The nickname "blob" for Physarum polycephalum comes directly from the 1958 American horror film The Blob, where a pinkish-red gelatinous creature from space devoured the inhabitants of a small town. The term was already circulating in French before 2019, before becoming the mainstream name.

The film The Blob (1958) in 30 seconds

The story

A meteorite crashes near Phoenixville, Pennsylvania. Inside: an extraterrestrial jelly, small at first, that begins to absorb everything it touches—dogs, humans, cinema projectionists. The creature grows by eating. Steve McQueen, then a young actor, saves the town by discovering that the cold immobilizes it.

Cultural impact

• Budget: very modest for the time—an independent production, far from studio standards
• Box office: several million dollars—a hit for the time
• Remake: 1988 (modernized special effects)
• Influence: an archetype of the gelatinous creature repeated in countless films and series

"Beware of the Blob!" — theme song from the 1958 film

The real blob: Physarum polycephalum

The real blob is a giant unicellular organism from the Amoebozoa supergroup, which lives in damp forests all over the world. Its lineage is very ancient—Amoebozoa date back more than a billion years according to molecular clocks—even if the age of the species itself remains undeterminable: myxomycetes almost never fossilize. It was described scientifically for the first time by Lewis David von Schweinitz in 1822—well before the film, therefore.

Film vs. Reality comparison

Criterion	The Blob (1958)	The real blob
Color	Pinkish-red	Neon yellow (sometimes orange)
Origin	Extraterrestrial meteorite	Terrestrial damp forests
Max size	Several meters	Can spread widely on its substrate in favorable conditions; in your box, expect a few centimeters
Eats what?	Humans, dogs	Oat flakes, mushrooms, bacteria
Speed	Chases people	From a few millimeters to a few centimeters per hour
Brain	Hostile, intentional	None, but solves problems (Nakagaki 2000)
Weakness	Cold	Drought + UV
Sexes	1 (unique creature)	720 mating types (Kawano et al. 1987)
Danger	Lethal in the film	No human infection described in the literature

The real scientific inspirations for the film

At the time (1958), screenwriters Theodore Simonson and Kay Linaker were inspired by:

• Slime molds already known to biologists
• Cold War paranoia and the fear of extraterrestrial invasions
• Giant amoebas observed under a microscope

So the film is indeed inspired by Myxogastria (the Physarum group, better known by the traditional name Myxomycetes), but by caricaturing them to the extreme to be scary.

Why does this myth persist?

Three psychological reasons:

1. The phobia of the formless

An organism without a fixed shape, which is constantly changing, triggers a primitive disgust—this is the human aversion to anything that lacks a clear "structure" (face, limbs, etc.). The blob ticks this box.

2. The fear of invasion

The film exploits the fear of an invader that is impossible to stop. No weapon, no possible reasoning. The same mechanics as Alien or Body Snatchers.

3. The disturbing color

The gelatinous pinkish-red evokes flesh, blood, internal organs—elements we are not supposed to see. The real blob is neon yellow, which is much easier to process.

The blob in modern pop culture

Movies & series

• The Blob (1958) — the original, the one that gave our myxomycete its nickname
• The Blob (1988) — remake with ambitious special effects
• The "slime" subgenre — a whole line of films with gelatinous creatures

Video games

• de Blob (THQ, 2008-2011) — gelatinous character who colors his world
• Pikuniku — round protagonist

When the real blob enters mainstream culture

• Paris Zoological Park, October 2019 — the moment the blob left labs to become a conversation topic: a park of the National Museum of Natural History exhibited it to the public, and the press seized upon it massively
• The Creeping Garden (2014) — British documentary entirely dedicated to Myxomycetes and those who track them
• "Élève ton blob" (Raise your blob) (CNES, 2021) — the educational operation that put a blob in the hands of thousands of French students

The real blob is more interesting than the film

Honestly, real science beats fiction:

• 720 mating types against 1 single creature in the film—not "sexes" in the animal sense, but compatibility types: matA (16 alleles) × matB (15) × matC (3) = 720 (Kawano, S., Kuroiwa, T., Anderson, R.W., 1987, Journal of General Microbiology, 133(9), 2539-2546) 🎯
• External memory: it avoids zones already explored thanks to the mucus trails it leaves behind—a sort of chemical thread of Ariadne (Smith-Ferguson, J., Reid, C.R., Latty, T., Beekman, M., 2017, Journal of Physics D) 🧠
• Solving a maze in a few hours, by connecting two food sources with an efficient route (Nakagaki et al., Nature, 407, 470, 2000) 🧭
• Reconstruction of the Tokyo area railway network in 26 hours, with efficiency comparable to the real network (Tero et al., Science, 2010) 🚦
• Travel to the ISS in 2021, awakened by Thomas Pesquet—much more stylish than the film 🚀

"The real blob doesn't eat humans. It just solves, without a brain, optimization problems that occupy mathematicians."

You can adopt the real blob (not the film one)

Rest assured: unlike the film, the real blob is associated with no human infection in scientific literature, and does not appear on any European regulatory list of biological agents at risk. No known allergens or toxicity to date—that said, it is not edible, and one washes one's hands after handling, as with any culture. And nothing sharp in the box: our kits contain tweezers and spatulas, never a blade.

FAQ — The Blob, film vs. reality

Is the 1958 film The Blob scientifically credible?

No. It is a horror film that exploits the fears of the 50s. No known organism on Earth resembles the creature in the film. However, the screenwriters were inspired by Myxomycetes—the group of the real blob.

Can the real blob grow as big as in the film?

Not quite as big, but still impressive. In nature, a single plasmodium can spread widely on its substrate—a dead tree trunk, a stump, leaf litter—when conditions are to its liking. At your place, in a Petri dish, it will be content with a few centimeters—and it's already very beautiful to see.

Where did the general public discover the real blob?

The major turning point was in October 2019: the Paris Zoological Park exhibited the blob to the public, and the topic went around the French media. Two years later, the "Élève ton blob" operation by the CNES put one in nearly 2,000 classrooms in France. On the documentary side, The Creeping Garden (2014) remains a great entry point to Myxomycetes.