It is a murderer, who's victim died more than four decades ago.
The amoebas killed a teenager in Richmond in 1968. They are being kept alive in a VCU Medical Center Research Lab.
Dr. Francine Cabral has spent the last 30 years trying to unlock the secrets of this rare but swift killer... Naegleria fowleri.
"It can be found in soil, it's in fresh water lakes and ponds," she said.
It's naturally occurring and can live in just about any freshwater environment — including stagnant sections of rivers or even your backyard pools. Scientists have even found it in tap water.
"This is an extremely rare disease. 10 million people can go swimming and maybe one person might become infected," said Cabral.
Last summer, 9-year-old Christian Strickland from Henrico County was that one person.
"He said 'I love you,' and I said 'I love you too.' It makes me proud, you know, even in those last moments of his life that he still put me first. He knew that would help me," said Christian's mother.
It's believed Christian contracted Naelgeria in the James River at a fishing camp. He's one of four known deaths in greater Richmond over 75 years. There's no cure, it's almost always fatal, there are only three known survivors in the world.
When Dr. Cabral heard about Christian last year, her heart broke. "All I could think about were my own children and how I would feel."
Cabral is one of only a few doctors worldwide to research the amoeba.
"It's very difficult to get funding to study a rare disease."
She said swallowing Naegleria does not hurt you. In fact, most people have been exposed in their lifetime. "It's perfectly happy out there to feed on bacteria and yeasts in the water and never have to infect a human. It's not a true parasite like others."
It's only in the rare instance when the amoeba is forced up the nose that a person become deathly ill. Dr. Cabral's found the amoeba in low levels in the James River and even in Lake Anna.
She's also isolated Naegleria in water samples from Florida, Arizona, even Connecticut. She emphasizes it's rare, but said there are ways to protect yourself.
"You can wear nose clips. If you're going to be jumping in water, even holding your nose will do the job."
She said don't stir up the sediment since the amoeba starts out in the soil. Always empty your kiddie pools every day and let them dry.
"If the amoeba are there and you dry them then the amoeba will die. They can't live without water," said Cabral.
Though it's been found in the tap water in other states, Cabral said she's tested the tap water in Richmond several times and has never run across Naegleria.