Philadelphia hip-hop heads know Lushlife as the local emcee behind projects such as 2013's "Toynbee Suite" or 2016's Ritualize. But now, he may just be their kids' favorite new author, too.

On Tuesday, Lushlife, real name Raj Haldar, 37, saw the release of his first book, P is for Pterodactyl: The Worst Alphabet Book Ever, a three-year project cowritten with college buddy Chris Carpenter and illustrated by Philly artist Maria Tina Beddia. The book is aimed at teaching young readers about one of the alphabet's dirtiest tricks: silent letters.

As of press time on Thursday, P is for Pterodactyl was number 5 on Amazon's best-seller list, behind the likes of Michelle Obama's Becoming and the most recent iteration of The Diary of a Wimpy Kid.

As part of the book, Haldar and Co. run down silent examples for each letter, like "O is for Ouija" or "T is for Tsunami," and use a few more examples in a sentence to drive the point home for confused kids. Beddia supplies whimsical, energetic illustrations to get the message across visually. Adults may even learn a thing or two, thanks to the inclusion of words like bdellium, a resin used in perfumes.

"No one who I know of would know what that is off the top of their head," Haldar, a New Jersey native, says. "This isn't an 'A is for Apple, B is for Boy' kind of deal."

While a children's alphabet book may not seem like the next logical step for a rapper, Haldar has some experience in kids' entertainment, thanks to his work with kids' TV network Nick Jr., for which he produces short, rap-based interstitials that teach viewers about science, like how a plant grows. As Haldar says, those clips typically earn upwards of 1.5 million views within a week of being uploaded online.

"It's weird to think that some of the most listened-to rap content I've created is in the 3-to-5-year-old demographic," he says.

Haldar, who does not have kids, says P is for Pterodactyl cropped up organically in 2016. Following the release of his seventh album Ritualize, Haldar was celebrating with friends — many of whom were new parents — in Philly when the conversation turned to children's literature. One friend brought up what Haldar calls "a hipster alphabet book," including examples like "Q is for Quinoa," and that was all it took to get the ball rolling.

"I don't know what bougie Whole Foods family [the book] was for, where the 3-year-old is like, 'Oh, quinoa,' " says coauthor Carpenter, 37, who works as a software engineer for a New York-based financial company. "I didn't know about quinoa until I was in college."

The absurdity of that example inspired Haldar and Carpenter, who has a 3-year-old daughter, to come up with other, similar takes on the alphabet book model, which ultimately evolved into P is for Pterodactyl. The first draft, Carpenter says, took about a day to write, but years of massaging and making changes followed.

"You have a rap dude and a computer programmer, and neither of us have any footprint in the publishing industry," Haldar says, adding that Sourcebooks Jabberwocky picked up the book after a friend of the rapper's at the magazine Mental Floss "connected a bunch of dots early on." From there, Beddia joined at the recommendation of another mutual friend despite a lack of funds to pay her upfront for her work.

"I had never gotten to illustrate a children's book, so I was more than happy to take that risk," Beddia, 34, says. "I loved the process, and that it's something I can get for my niece and nephew for Christmas. It's something that I actually helped bring to life."

However, while navigating the publishing industry was a challenge, actually crafting the lines in the book was a little more familiar for Haldar, who has been writing his own rhymes for more than a decade. Writing bars for rap songs and lines for kids' books is pretty similar, considering each form uses language efficiently to effectively tell a story or make a point. P is for Pterodactyl, for example, is less than 500 words long by Haldar's estimation, which makes its economy of language as important as in a good rap, even though the book doesn't rhyme.

"It wasn't so far off," he says. "The way I write raps, every bar is considered very deeply on the level that I am trying to boil things down to exactly what I am trying to express. We spent a year poring over every little detail of every word to make sure it sounded right and felt right."

Haldar says more kids' content is part of his future. The rapper is open to continuing P is for Pterodactyl as a series, and has "some other projects on deck in children's literature" that he can't yet discuss.

Despite his success in the kiddie realm, however, Haldar is also still focusing on music. He is hard at work on a new release with Skull Eclipses, a project with Austin-based producer Botany that will "start to hit people's ears" in mid-2019. New tunes under the Lushlife moniker, as well as a documentary, are also slated for 2019, he says. Ditto for his role as stadium DJ for the Eagles.

"On the music side, I haven't pumped the brakes at all," Haldar says. "I'm just adding more to my plate."