All grown up: Child star transformations

Jonathan Taylor Thomas turned 34 on Tuesday, September 8, and fans are wishing they could see him more. He pops up occasionally, like on "Home Improvement" co-star Tim Allen's ABC series "Last Man Standing," which feels like deja vu all over again.

All grown up: Child star transformations

Thomas (at right with Zachery Ty Bryan, left, and Taran Noah Smith) first snagged hearts as one of the sons on Allen's hit '90s show.

All grown up: Child star transformations

The late Steve Irwin's daughter, Bindi Irwin, has grown up to be quite the conservationist, just like her dad. She's also become a bit of a celeb like her father and was recently recruited for season 21 of "Dancing With the Stars."

All grown up: Child star transformations

"Crocodile Hunter" Steve Irwin with daughter Bindi in 2006 at Uluru, Australia.

All grown up: Child star transformations

Matthew Lewis, who starred as the shy and unassuming Neville Longbottom in the "Harry Potter" movies, has grown into a strapping young man. He buffed up for roles as a soldier in "Bluestone 42" and an athlete in "Me Before You."

All grown up: Child star transformations

Lewis sported a slightly different look as Neville in the "Harry Potter" films.

All grown up: Child star transformations

Along with her "Harry Potter" co-star Lewis, Emma Watson's proving that she's not little Hermione anymore. The actress played a thief in 2013's "The Bling Ring" and an ax-carrying marauder in "This Is the End."

All grown up: Child star transformations

A young Watson as frizzy-haired Hermione in "Harry Potter."

All grown up: Child star transformations

All grown up: Child star transformations

As a child, Radcliffe may have become the world's favorite wizard as "Harry Potter."

All grown up: Child star transformations

Jaden Smith has grown up since his breakout role with his dad, Will, in "The Pursuit of Happyness." Although he once again starred with his father in 2013's "After Earth," Jaden isn't a kid anymore.

All grown up: Child star transformations

Smith was a baby-faced child star in 2006's "The Pursuit of Happyness."

All grown up: Child star transformations

Jayden's sister, Willow, has followed her big brother into show business. In 2011, she had a hit single with "Whip My Hair."

All grown up: Child star transformations

Smith appeared with her dad in the 2007 film "I Am Legend."

All grown up: Child star transformations

Fans were excited to see a grown-up Haley Joel Osment in the "Entourage" movie in 2015.

All grown up: Child star transformations

Osment first found fame as as the child star of 1999's "The Sixth Sense."

All grown up: Child star transformations

Tyler Posey appeared on Fox's Teen Choice Awards in August 2014 in Los Angeles with Jennifer Lopez. It was a throwback to years earlier when ...

All grown up: Child star transformations

Posey co-starred with Lopez in "Maid in Manhattan" in 2002.

All grown up: Child star transformations

Keke Palmer became the first black Cinderella on Broadway in 2014. She's worked steadily through most of her childhood.

All grown up: Child star transformations

Palmer got her first major role in "Akeelah and the Bee" in 2006.

All grown up: Child star transformations

Angus T. Jones, left, grew up before viewers' eyes on the hit CBS series "Two and a Half Men."

All grown up: Child star transformations

Jones was a chubby-cheeked youth in 2003 at the premiere of his movie "Bringing Down the House."

All grown up: Child star transformations

All grown up: Child star transformations

Back then, Bieber was a fairly innocent teen heartthrob.

All grown up: Child star transformations

Twerking Miley Cyrus (with Robin Thicke during the 2013 MTV Video Music Awards at in New York) was a far cry from the child star many remembered.

All grown up: Child star transformations

In 2006, Cyrus was known as the star of Disney's "Hannah Montana."

All grown up: Child star transformations

Selena Gomez's appearance hasn't changed dramatically since she starred on the Disney Channel's "Wizards of Waverly Place," but her work sure has. Gomez has stretched herself with more mature content, such as the risqué movie "Spring Breakers" and her suggestive single "Come and Get It."

All grown up: Child star transformations

Gomez was still a youngster in 2007 when she attended the premiere of Walt Disney's "Pirates Of The Caribbean: At World's End."

All grown up: Child star transformations

Vanessa Hudgens has appeared in more adult projects such as "Spring Breakers" and "Machete Kills."

All grown up: Child star transformations

Hudgens came to fame as a Disney Channel star in 2006 but soon stepped away from her wholesome "High School Musical" roots.

All grown up: Child star transformations

Oh, how you have grown, Zac Efron. The "High School Musical" star is now appearing in more adult roles, including 2015's "We Are Your Friends."

All grown up: Child star transformations

His fans will still always remember him as the fresh-faced Troy Bolton in the "High School Musical" franchise.

All grown up: Child star transformations

Keshia Knight Pulliam held a pretty iconic role as a youngster, but these days, she is all grown up and appearing in TV movies like "The Love Letter."

All grown up: Child star transformations

Pulliam will always be remembered as Rudy Huxtable on "The Cosby Show."

All grown up: Child star transformations

Raven-Symone now has a gig as one of the co-hosts on "The View."

All grown up: Child star transformations

Her breakout role as Olivia on "The Cosby Show" led to her very successful Disney series "That's So Raven."

All grown up: Child star transformations

Alyssa Milano starred as a preteen on the '80s series "Who's the Boss?" but also had a hit as an adult with "Charmed."

All grown up: Child star transformations

Milano's role as Samantha Micelli, the daughter of a former athlete who accepts a job as a housekeeper for an advertising executive with a young son on "Who's the Boss?" first made her a star.

All grown up: Child star transformations

All grown up: Child star transformations

His "Home Alone" films are just as popular now as they were in the 1990s.

All grown up: Child star transformations

"Mad Men" fans have watched Kiernan Shipka grow up as Sally, the daughter of protagonist Don Draper. Having starred on the series since she was 7, Shipka's gone from being a little ballerina with a lisp to a teen girl with enviable poise.

All grown up: Child star transformations

Shipka as a youngster when she first snagged the role of Sally on "Mad Men."

All grown up: Child star transformations

One minute, Abigail Breslin was a 10-year-old "Little Miss Sunshine," and the next thing we know, she's flashing her bra in 2011's "New Year's Eve." The actress is now grown-up enough to take on the older sister role, as she did in the 2013 release "Ender's Game." She also nabbed a role in the 2015 TV series "Scream Queens."

All grown up: Child star transformations

Many still remember the actress as Olive Hoover in the 2006 film "Little Miss Sunshine."

All grown up: Child star transformations

Designers Mary-Kate Olsen, left, and Ashley Olsen are a force to be reckoned with in the fashion world.

All grown up: Child star transformations

The Olsen twins have been in the entertainment industry since they were literally in diapers; the pair took turns playing Michelle Tanner on "Full House" from 1987 to 1995. They went on to star in their own movies before starting their fashion lines, Elizabeth and James and The Row.

All grown up: Child star transformations

These days, Jonathan Lipnicki is old enough to play Renee Zellweger's love interest.

All grown up: Child star transformations

He's best known for his role as Zellweger's cute-beyond-words son in 1996's "Jerry Maguire."

All grown up: Child star transformations

Chloë Grace Moretz was a "Kick-Ass" actress even as a kid. She outgrew her baby look but not her action moves: The star appeared in the "Kick-Ass" sequel in 2013.

All grown up: Child star transformations

As a child, Moretz also had starring roles in movies like "The Amityville Horror," which she appeared in at age 8.

All grown up: Child star transformations

All grown up: Child star transformations

Fanning was quite the tyke on "The Tonight Show with Jay Leno" in 2002.

All grown up: Child star transformations

Nowadays, Lindsay Lohan is known more for troubles than for her career.

All grown up: Child star transformations

Lohan showed off her acting prowess at 12 when she played a set of identical twins in the 1998 remake of "The Parent Trap." She went on to star in movies like "Freaky Friday" (2003) and "Mean Girls" (2004), but her tumultuous private life soon interfered with her career.

All grown up: Child star transformations

Anna Chlumsky landed a hit comedy with HBO's "Veep" and welcomed her first child in 2013.

All grown up: Child star transformations

Chlumsky became a star at age 11 thanks to her role in 1991's "My Girl."