When Haus the German Shepherd started acting strangely around his human sister, the girl’s grandmother became concerned. So she went to see what was going on – and walked in on a frightening scene.

Molly DeLuca was playing outside alone with the family’s new rescue dog, Haus, when the little girl let out a terrifying cry. The family then rushed out to the yard – where a horrifying scene met them. At first, they saw the dog’s erratic behavior. Then they saw the blood.

Adam and Donya DeLuca live in Tampa, Florida, with their two children, seven-year-old Molly and her younger brother, Joey. For a long while, they also lived with a German Shepherd-mix rescue dog called Bailey. That furry family member meant the world to Donya.

After all, Bailey had been with Donya for the most emotional moments of her life until his passing in March 2016. So just days after his death, she decided to rescue again. “I knew I had to do something good with Bailey’s loss,” Donya wrote on Facebook on May 22, 2016.

Despite Adam’s initial reluctance, he went along with his wife’s wishes, and they adopted a German Shepherd called Haus. The family’s fears about the adoption being premature were immediately forgotten, though. Donya described the transition in an interview with the Today show on May 16, 2016.

“Haus just bonded with all of us so quickly,” Donya reported. “It was like he was always part of our home; even the neighbors took to him. It was meant to be.” The dog especially loved the children, it seemed, and he took it upon himself to make sure that they were safe.

The mom-of-two elaborated, “Especially at night, he’s very protective of the kids. He follows them around; he takes care of them.” Additionally, Donya told ABC News that it’s common practice for Haus to patrol the garden with the intention of guarding his charges.

So, two months after his adoption, Haus accompanied little Molly when she wandered outside into the DeLucas’ yard. Molly then went to gather up dog toys in the garden, and the big German Shepherd continued to follow her. However, something other than chew-toys was lurking in the grass that day.

As Molly’s grandmother watched from the doorway, Haus started acting in a strange way. She observed him leaping at something in the vegetation several times, but each time he recoiled as if struck. Consequently, grandma DeLuca went over to investigate.

That’s when Molly’s grandma noticed that Haus had shielded the little girl from an eastern diamondback rattlesnake. These diamondbacks are not only the biggest and heaviest rattlesnakes in the U.S., but they’re also North America’s deadliest serpents. One report even suggested that for humans their bite has a 30 percent chance of ending in a fatality.

Although diamondbacks are not normally violent by nature, this one clashed with Haus, who fought to protect Molly. Yes, the erratic behavior that grandma DeLuca witnessed was Haus attacking the snake. She also saw the dog recoiling from the serpent’s bite when the diamondback sank its fangs into him.

For Molly’s part, the whole ordeal terrified her. “I was really scared,” she told ABC News on May 18, 2016. Her mother added, “Molly wasn’t particularly paying attention, [but] she saw the aftermath.” Still, what the little girl had experienced could have been traumatic.

According to grandma DeLuca, though, the diamondback’s bite left Haus’ leg “pouring” blood. And despite being stood up, Haus couldn’t hold any weight on his front paw. Minutes later, the dog’s condition had deteriorated to the point where he couldn’t remain upright.

Even more worryingly, Molly’s grandmother could barely tell if Haus was breathing as he was salivating uncontrollably. So, after making sure Molly was okay, she took Haus to an emergency veterinary surgery. Luckily, it was close by, and the vet began immediate snakebite treatment on the German Shepherd.

Donya then joined her daughter and mother at the Tampa Bay Veterinary Clinic, where the vets revealed some news. Usually, they said, if a snake bites a dog, the canine retreats. However, Haus had apparently been fighting for his family and, as Donya put it, he “stood his ground.”

In fact, the diamondback had bitten Haus three times, flooding his system with venom. He’d absorbed so much of it, in fact, that veterinarians put him on a drip immediately, delivering the equivalent of nine anti-venom doses. Haus also required a blood transfusion as a result of the attack.

Yet as Haus’ life hung in the balance, the unavoidable vet bills increased beyond affordability for the DeLucas. But his family couldn’t just let him die. With that in mind, they set up a crowdfunding page to help with the medical costs.

The public later donated far in excess of the DeLucas’ $28,000 goal. Their GoFundMe campaign actually reached a whopping $51,000. And luckily, Haus fought just as hard for his own life as he did for Molly’s, and – thanks to the vet’s prompt treatment – he was preparing to go home just seven days later.

DeLuca couldn’t believe how much Haus had recovered in such a short time. “I would almost say it seems miraculous, based on the turnaround that we had from last week,” she told ABC News. “We’re just really, really happy.”

So how is Haus these days? Well, on May 15, 2017, DeLuca provided an update in response to his curious fans. “We’ve gotten a lot of requests for updates so I wanted to reach out,” she wrote. “Haus is doing very well. He is happy and healthy with very minimal lasting effects.”

And now this brave dog is giving back to Heidi’s Legacy, the local shelter that he came from. The DeLucas are acting as foster parents for dogs in need of a home, too, and Haus is helping them. Even after such a traumatic experience, it seems that you can’t take the hero out of Haus.