(Mental Floss) -- In his victory speech on Tuesday night, Barack Obama promised his daughters Sasha and Malia that they'd get to bring a new puppy with them to the White House in January.

President Bush's dog Barney, left, plays in 2001 with Spot, the offspring of George H.W. Bush's dog Millie.

It's a good thing Obama said "Yes, we can" to the girls' request to getting a dog; for all of his charm, ability, and oratorical flair, he could never be our nation's chief executive without a White House pet.

Counting Obama, the country has had 44 Presidents, and only two of them -- Chester A. Arthur and Franklin Pierce -- left no record of having pets.

Like Obama himself, the family pooch will have some big shoes to fill. Previous White House pets have set the bar pretty high. iReport.com: What pet would you want if you lived in the White House?

Here are a few of our favorites: Watch Obama on "mutts like me" »

1. Billy: Calvin Coolidge's pygmy hippopotamus

Calvin Coolidge may have been known for his reticence, but he showed little of his trademark reserve when it came to acquiring pets.

After taking over the presidency upon the death of Warren G. Harding, Coolidge assembled a menagerie that would rival most zoos' collections.

He had six dogs, a bobcat, a goose, a donkey, a cat, two lion cubs, an antelope, and a wallaby. The main attraction in his personal zoo, though, was Billy, a pygmy hippopotamus. Watch new baby pygmy hippo »

Billy was born in Liberia, but was captured at a young age.

He came into the possession of tire mogul Harvey Firestone, who gave Billy to President Coolidge as a gift, possibly because Firestone didn't want to feed the critter. (Even a pygmy hippo is still quite rotund; Billy was six feet long and weighed upwards of 600 pounds.)

Coolidge donated Billy to the Smithsonian National Zoological Park. Because there were only a handful of pygmy hippos in the U.S. at the time, Billy quickly went to work as a stud, an endeavor at which he found some success.

He sired 23 little hippos, and many of the pygmy hippos you see in American zoos today are his offspring. Mental Floss: 7 crafty zoo escapes

2. The White House gators

Herbert Hoover wanted to put a chicken in every pot, a car in every garage, and ... a gator in the Oval Office? It's true.

Hoover owned a slew of dogs, but those weren't his only pets. His second son, Allan Henry Hoover, owned a pair of gators that were occasionally allowed to wander around the White House grounds.

Sound crazy? Blame John Quincy Adams for setting the precedent. The sixth president also had a pet gator. His was a gift from the Marquis de Lafayette; it lived in a bathroom in the East Room of the White House. According to some reports, he enjoyed using the gator to scare his guests.

3. Fala: FDR's traveling companion

What do you get the Depression-conquering president who has everything? A lapdog.

In 1940 Franklin Roosevelt received a Scottish Terrier puppy named Big Boy as an early Christmas gift from a family friend.

FDR immediately realized that Big Boy was no name for a presidential companion and rechristened the pooch Murray the Outlaw of Falahill, after a Scottish ancestor. For the sake of simplicity, though, he called his new pal Fala.

After that, Fala became FDR's inseparable companion and traveled everywhere the President went.

The dog "gave" $1 a day to the war effort, generosity that earned him the rank of honorary private in the Army. Each morning when FDR's breakfast tray came in, it included a bone for Fala.

Fala also made a famous appearance in one of his master's speeches. When FDR was decrying personal attacks from his political opponents, he jokingly said that it was okay to mock him, but leave Fala alone.

"You know, Fala is Scotch, and being a Scottie, as soon as he learned that the Republican fiction writers in Congress and out had concocted a story that I had left him behind on the Aleutian Islands and had sent a destroyer back to find him -- at a cost to the taxpayers of two or three, or eight or 20 million dollars -- his Scotch soul was furious.

"He has not been the same dog since!"

Fala stayed with FDR until the President's death in 1945 and lived in the care of Eleanor Roosevelt until his death in 1952. Mental Floss: 6 utterly loyal dogs

4. Millie: Literary sensation

When George H.W. Bush took office in 1989, he brought his pet springer spaniel Millie to the White House.

The bubbly canine won over the nation's heart so completely that she even collaborated with the First Lady on Millie's Book: As Dictated to Barbara Bush.

Millie brought further joy to the Bush family when she gave birth to a litter of six presidential puppies in 1989.

Just as her master helped slip one of his boys into the White House, so did Millie: when George W. Bush moved into the Oval Office, so did his dog, Millie's son Spot Fetcher.

5. Barney, Miss Beazley & India: The current residents

Sadly, Spot Fetcher had to be put down in 2004, but the Bushes aren't pet-deprived now.

They have a pair of Scottish Terriers named Barney and Miss Beazley, both of whom have websites and appear in White House-produced web videos. (Your tax dollars adorably at work!) The Bushes also have a black cat named India, who also goes by "Willie." Watch Barney bite a reporter »

The name India rankled some citizens of the country of the same name to the point that many Indians supposedly named their dogs "Bush."

The name wasn't meant to be controversial, though; the Bushes merely named their cat after Ruben "El Indio" Sierra, who played for the Texas Rangers while George W. owned the team. Spot Fetcher was similarly named after former Rangers middle infielder Scott Fletcher.

Other first pets of note:

Mr. Reciprocity and Mr. Protection -- Benjamin Harrison's two opossums. Harrison's son Russell also had a pet goat named Old Whiskers.

Pauline -- The last cow to live at the White House. She made milk for President Taft's consumption.

Old Ike -- To save cash during World War I, Woodrow Wilson brought in a flock of sheep to take care of the White House's groundskeeping duties. Old Ike, a ram, supposedly chewed tobacco.

Laddie Boy -- Warren G. Harding's beloved Airedale who had his own seat at Cabinet meetings and gave a 1921 "interview" with The Washington Post in which he talked about Prohibition and shortening the workday for guard dogs.

Liberty -- Gerald Ford's golden retriever hung out in the Oval Office and could supposedly read a sign from Ford that she should go be affectionate to guests -- a cute and cuddly way to gracefully end the President's conversations.

Socks and Buddy -- President Clinton's faithful cat and the chocolate lab he acquired while in office. Socks didn't like Buddy's youthful friendliness, so the two pets had to be kept separated at all times. The tensions were so bad that the family couldn't keep both pets at the end of Bill's second term, so Socks went to live with Clinton's secretary, Betty Currie.

Gamecocks -- Ulysses S. Grant supposedly kept some gamecocks at the White House.

Two tiger cubs -- Martin Van Buren received the cats as a gift from the Sultan of Oman. Congress supposedly made him give the gift to a zoo.

Satan -- One of Abigail Adams' unfortunately named dogs. She called the other one Juno.

Jonathan Edwards -- Theodore Roosevelt received this black bear cub as a gift from supporters in West Virginia who gave the bear the name, he wrote to a friend, "partly because they thought they detected Calvinistic traits in the bear's character."

Dr. Johnson, Bishop Doane, Fighting Bob Evans, and Father O'Grady -- Teddy Roosevelt's kids also had these tremendously named guinea pigs.

Josiah -- Roosevelt also had a pet badger, of course.

Bonus trivia: Checkers

Nixon's dog was immortalized in the "Checkers speech," which Nixon gave while facing allegations of illegal campaign contributions.

He said the only gift he'd accepted was a cocker spaniel named Checkers for his daughters. Mental Floss: Why was the 'Checkers speech' so important?

Checkers, however, was never the White House dog. This scandal bubbled up while Nixon was Eisenhower's running mate in the 1952 election, and Nixon gave the Checkers speech to convince Republicans to keep him on the ticket.

Although the speech was a success and Nixon later made it to the White House, Checkers never got to be First Dog; he passed away in 1964.

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