Australia is one of the few continents that has all three groups of mammals — monotremes, marsupials and placentals — while also being home to more than 800 species of birds, two crocodile species, 4,000 fish species and 50 types of marine mammals. Considering Philadelphia 76ers standout rookie Ben Simmons’ love for animals, it certainly seems quite fitting that he hails from Australia.

“Being in Australia, being around animals at a young age, I’ve always loved animals,” Simmons said. “My first pet was my golden retriever. I got him at 7 years old. I grew up around animals. My sisters and brothers had cats. I love all kind of animals.”

Simmons was born in the Melbourne suburb of Fitzroy on July 20, 1996, to an Australian mother, Julie, and American father, Dave, who played professional basketball in Australia for 12 seasons. During Simmons’ early years, his family with six children bounced around Melbourne, Sydney, Newcastle and Canberra to follow Dave Simmons’ basketball career.

Through all the moving around, Simmons always had a friend in the family dog, Jasper, and dreamed of more animals to befriend.

“He had a dog and a cat,” said TCU assistant men’s basketball coach David Patrick, who is Simmons’ godfather. “He was always asking parents to buy him birds and other things he wanted. Obviously, when you are young, you don’t get everything that you want.

“They moved into so many places when he was a young kid. I know his dog, Jasper, and his cat were two things that wherever they moved came with him. Ben was always a quiet kid. … He was always on his own, with his dad or with those damn animals, kind of away from everything.”

Simmons often had an odd pet on his shoulder that his half-brother, Sean Tribe, wasn’t excited about.

“He had a rat as a kid as well,” Tribe said. “He was like 6 or 7 years old. He had a white rat that would chill on his shoulder and go around the house with it. We were weirded out about that. He was a different kid. He was always growing up around animals. And with Australia being known for its wildlife, it wasn’t a big deal.”

Simmons also grew up loving basketball and rugby. After moving on from rugby, he became an Australian youth basketball star who moved to the United States in January 2013 to play against elite high school competition at Montverde Academy in Florida. The 2015 McDonald’s All-American was regarded as the No. 1 player in his prep class by ESPN.com. Simmons chose to play for Louisiana State University, where Patrick was an assistant coach at the time.

Off the court, Patrick recalled Simmons going to a pet store in Baton Rouge, Louisiana, to buy rats. But this time, it wasn’t to have as pets.

“He had a cat at LSU that they called Tiger. Then all of the sudden he was buying rats to feed his snake. He had to feed his snake rats,” Patrick said.

Simmons enjoyed going to the Melbourne Zoo as a kid and went last offseason. He has played with koalas, penguins and seals. He also had a lizard and birds when he was at LSU.

But one beast Simmons didn’t toy around with was Mike the Tiger, a mixed-breed Bengal tiger that resides on LSU’s campus in a cage and serves as the school’s official mascot.

“Mike the Tiger, I definitely stopped by all the time to see him. Not in there in the cage. Just outside. He’d probably kill me. If it was a baby, I would go in there,” Simmons said.

Simmons averaged a double-double of 19.2 points and 11.8 rebounds during the 2015-16 season at LSU, but the school failed to make the NCAA tournament. The 6-foot-10 point forward was selected first overall in the 2016 NBA draft by the 76ers. Simmons, however, suffered a fracture of the fifth metatarsal bone of his right foot that caused him to miss the entire 2016-17 NBA season.

To help get his mind off missing basketball, Simmons turned to animals with the aid of Tribe, who lived with Simmons in Philadelphia and ended up spending a lot of time with a revolving door of animals while his brother was often on the road with the Sixers.

“When we got to Philly, he said he wanted a cat and not to worry about it. The cat had some kind of blood disease, so we had to take it back to the breeder,” Tribe said. “Then he said, ‘Now I want a dog.’ He did the research and said he wanted a Cane Corso. So we’re living in an apartment, so I don’t know a Chihuahua from a German shepherd. So I was like, Cane Corso, cool. Then we get the puppy and it’s the size of a grown dog already. This is a huge dog already.

“Fast-forward to now, one of the Sixers’ trainers has the dog. He was too big for the apartment. He’s 120 pounds. It would have been like having a third roommate.”

With a cat and dog gone, an injured Simmons searched the internet for another animal. He first chose a Savannah cat that was first bred in 1985 and was the ancestor of the African serval. The bred domestic cat has a cheetahlike appearance and was once deemed the world’s tallest domestic cat by the Guinness Book of World Records.

Everything was fine when Simmons and Tribe had one Savannah cat. But when the second was purchased after Simmons’ urging, that’s when all the scratching, clawing and problems started.

“So we start with one. It’s all good, and everything is cool,” the 31-year-old Tribe said. “Then Ben, being the 20-year-old that he is, says, ‘He needs a friend. We need to give it a friend.’ So he gets a male one this time, and this cat is crazy. It doesn’t want to eat. It’s hiding from us. Every time we go near it, it’s scratching. You can’t go near this cat. You give the cat a bowl of fruit and it’s clawing at your hand when you put the fruit down. It’s like a wild animal.

“We had them for about four or five months, and I told Ben, ‘We can’t have these cats anymore. This is crazy.’ He was going on a road trip while he was injured, and I told Ben, ‘I am going to call the breeder and tell them we can’t quite look out for the cats anymore and they can find them a better home.’ He said, ‘Cool.’ ”

Tribe sent the female cat back without any issue. Sending back the male cat, however, presented a challenge that Tribe will never forget and perhaps never forgive Simmons for.

Tribe had an extremely hard time getting the cat in the cage to take to the airport and was scratched in the process. Upon arrival at American Airlines check-in at the Philadelphia International Airport, he said he was told the cage needed to be scanned separately before he was allowed to check the cat in. Tribe said he begged the baggage handlers to let him have the cage scanned without taking the cat out. The answer was no.

“I am running around the apartment with an oven mitt and a stick to try to herd this cat into the cage, and this cat is attacking me,” Tribe said. “Meanwhile, Ben is asleep on the West Coast on his road trip. He has no clue what is going on. I finally get the cat into the cage and to the airport and put the cage up on the airport bench and say, ‘Cool.’ So they say, ‘Just take the cat out, we need to scan the cage.’ I said, ‘Look, you don’t understand.’ ”

A frustrated and nervous Tribe followed the protocol and put the angry cat in his Range Rover while the cage was scanned. He was then told he had to bring the cat solo from the car to keep from having to scan the cage again. Tribe enlisted two American Airlines baggage employees to help him in the parking lot to get the cat inside an empty, tall printer paper box to hold him until he could be put back inside the cage.

And after being involved in the challenge to catch an enraged cat in a Range Rover, the American Airlines baggage attendants probably wished they had listened to Tribe in the first place.

“Now the cat is at the back of the Range Rover staring at me …,” Tribe said. “I’m trying to make it move and get in the box. It lunges toward me and goes to the front of the car. I said, ‘All right, cool.’ Then the cat leaps onto the passenger window and the baggage guys were like, ‘Oh s—.’

“Then I move the box toward him and the cat falls into the box. This is too good. The cat is trying to bust out of the box. I run into the airport, get the cage, find the small crack on the cage and get the cat in.”

With his hands bleeding, Tribe was able to finally get rid of the rowdy feline. A peeved and spent Tribe woke up his brother on the West Coast to curse him out on FaceTime.

“I ‘FaceTimed’ Ben straight away. My face is sweating. My hands are bleeding. I said, ‘F— you. … I don’t care if you’re asleep. … You and your f—ing animals,’ ” Tribe said.

Looking back on his Savannah cats experiment, Simmons had sympathy for his brother.

“They got crazy. One made the other one crazier. That messed up the flow when I got the second one. I got scratched a couple times, but nothing crazy. My brother had more problems than me,” Simmons said.

Not giving up on animals, Simmons immediately searched for a dog. This time, he chose well. Simmons went to Morgan Hill, California, where he purchased a French bulldog when the Sixers played against the Golden State Warriors last season. With no room in his condominium in Philadelphia to house his beloved dog named Flash, Simmons is staying at the house where his parents live in the city. He also has a fish tank at his condominium with an array of fish.

“The main problem was who is going to take care of them and feed them when I’m not there. But my parents moved there now, so that’s easy. They’re willing to help,” Simmons said.

Tribe said it was really hard for his brother to fight through rehabilitation while missing his first season in the NBA. He eventually realized that Simmons’ infatuation with animals last season was not only because of his love for them, but also a means to get his mind off basketball.

“It was a distraction and something to take his mind off of it. That was the main thing. At the time I was thinking, ‘Why do we have these pets?’ Now, I’m like, ‘All right, maybe he did need something to take his mind off of things.’ I think it helped,” Tribe said.

Said Simmons: “I was frustrated because I couldn’t help my team.”

Simmons is more than helping the Sixers win now with his all-around play early into his rookie NBA season.

Simmons is averaging 17.8 points, 9.2 rebounds and 7.5 assists entering Wednesday’s game against the host Los Angeles Lakers. The 21-year-old has two triple-doubles and eight double-doubles in 13 games. The long-rebuilding Sixers have a 7-6 record and hopes of making the postseason for the first time since 2012, with Simmons and budding star center Joel Embiid leading the charge.

“This guy is a bulldozer like LeBron [James] or Magic [Johnson],” Warriors head coach Steve Kerr said. “Just powerful. Springy. He has a strange game because he is not a shooter. He finds different ways to score the ball that are unorthodox and difficult to guard. It’s fantastic that he and Joel are playing well. It’s so good for the league and fun to watch.”

At some point, Simmons plans to buy a home in Philadelphia that will likely have a huge backyard to fit his beloved animals. That backyard could rival the Melbourne Zoo when, as his already concerned brother believes, it will be a “straight-up zoo.”

“Once I get a house, I will have a lot more animals and pets. I don’t want too many animals. I want two dogs. I thought about getting a big crocodile. But that’s probably too much,” Simmons said.

Said Tribe: “I am going to feel bad for the landscaper when they’re designing it all. ‘I want a doghouse here and maybe a birdhouse there.’ He is going to go pretty [crazy] on it.”