Halley's First Birthday is the first official episode of Astroblast, after the show's pilot episode Halley Vivian and the Great White Thing, and the first episode of Season 1.
- Grandpa Ben
Matthew and Olivia strive to make Halley's first birthday a memorable one. They did, but under the wrong circumstances. Meanwhile Halley wants to eat dog food so she can be just like Bruce, eventually selling the other babies on the idea.
One morning, Halley Vivian is woken up by her parents who wish her a happy birthday: her very first, in fact. Once she's changed and dressed in her special birthday outfit (which consist of a Mario-like red T-shirt with overalls instead of what will be the series normal of pink nightgown) Olivia takes her downstairs for breakfast before her party begins.
Olivia and Matthew feel thoroughly prepared for this special occasion by consulting Lipschitz and creating a birthday checklist. The adults don't notice that Halley is watching a dog food commercial on TV. Feeling inspired by the ad, Halley breaks out of her highchair and crawls over to her dog Bruce's food bowl (full of canned dog food). At the last minute Grandpa Ben catches Halley and tells her she doesn't want dog food, she wants her baby food breakfast. But when Ben looks at Halley's baby food he admits that dog food does look more appetizing by comparison!
The day rolls on and Caroline and Luke DeVille arrive for the party with their twins, Comet and Venus, and Jet Mender, the neighbors son. When they're all gathered in the playpen, Halley tells them about the dog food commercial, and her belief that if they eat dog food, they'll turn into dogs. The other babies find this appealing and decide they want to be dogs, too. But before they can leave the playpen, the grownups put party hats on the babies and snap pictures, though the babies aren't thrilled by either one.
Soon, Matthew's older brother Matt arrives with his daughter Sputnik (who, not unlike Halley, is wearing a special birthday party dress for the occasion). Sputnik gleefully poses for pictures with the babies, though roughly. Halley tells Sputnik about the dog food, who enjoys the idea of biting the mailman and agrees to go along with Halley's plan to get dog food. But before they can do anything, it's time to open presents. Sputnik is greedy and wants Halley's presents for herself. Matthew made Halley's present himself: a remote control flying saucer. Olivia and Grandpa Ben both doubt that even a grownup can fly it, but Matthew insists Halley can figure it out.
The doorbell rings, signaling the arrival of the puppet stand and puppets the Vivian's booked for the party. But there are no professional puppeteers to go with the stand, leaving Matthew and Matt to perform themselves (and Olivia worrying that her daughter's first birthday won't be perfect). They decide to perform the climax of Little Red Riding Hood, but they quickly begin to argue over how the lines go. Ben tries to tell them to cut it out (with a puppet of his own), however it doesn't work and they continue to bicker. Meanwhile Grandpa Boris, Olivia's father, complains about the cake she baked. Olivia baked a carrot cake, but Boris says a chocolate cake is more suitable.
With the adults distracted, first Halley, then the rest of the gang, go to the kitchen, but find Bruce's bowl licked clean. They find another can on the counter, but have difficulties getting it down on their own. They use Matthew's present to help, but wreck the kitchen and the cake in the process! Fortunately, Ben opens the can of dog food for Bruce. Bruce isn't interested in eating right now, so the babies eagerly help themselves...and quickly spit it out (except for Venus)!
Nothing happens at first, but then Halley says she feels something, and starts to bark and crawl around. Comet and Venus say they have fleas, Jet hopes he can grow fur, and Sputnik hopes the mailman comes soon. All of them start acting like dogs, which attracts the notice of the adults. They feel happy seeing this moment, because even though the day was far from perfect they're all having a good time. A picture of this is taken, which is forever included on the pages of the photo album documenting Halley's first birthday.
- This episode debuted on the same date as the other two original Sorout shows Ruff Ruff, Tweet, and Dave, and The Chica Show. Ruff Ruff, Tweet, and Dave was the first to air, then Astroblast, and then The Chica Show.
- In this episode Halley is wearing a red shirt, though almost all of the time, she wears a pink nightgown further in the series.
- When Halley turns on the television the Sprout logo is visible in the corner of all channels she views.
- This is the first episode where Gigi Abraham voices Halley Vivian.
- This is presumably the first time characters other than the Vivian's see Bruce, considering the fact they believe him to be Halley after eating dog food.
- This is the first appearance of Jet, and Sputnik, and the first appearances of Sputnik's dad and Matthew's older brother, Matt, Olivia's parents and Halley's maternal grandparents, Boris and Claire, and Comet and Venus' parents, Luke and Caroline, but not the first appearance of some other main characters such as Halley, Venus, Comet, Olivia, Matthew, Ben and Bruce, who appeared previously in the unaired pilot.
- On the receipt for the Puppet Stage and the Puppets, Matthew & Olivia's address was seen and is 1258 N. Highland. From 1988 to 1995 this was the address of Sprout.
- Animation Error: In this episode, Sputnik was wearing the special party dress. But near the end, while the babies act like dogs, Sputnik was wearing her normal dress, not originally introduced until the next episode.
- This episode shows the entire original cast of Astroblast except for Chas Mender, who wasn't introduced until Barbecue Story. Lillian and the Jones' weren't created until Season 2 of the series.
- From this episode until "Moving Away", episodes of the series would typically air at 2:00 PM EST on Sunday afternoons.
- Behind Boris and Minka in the doorway is a green solid object, not grass because it fills the whole space up.
- The title card and Matthew's first line, "Good morning, Champ," are cut out from digital copies of the episode.
- When the babies were acting like dogs Sputnik was in a suit but when they were acting like dogs Sputnik was in her clothes she would wear for nearly all the series.
- When Olivia opens the door for Boris and Minka, we see her right hand raised, frozen waving. Her left hand rubs the area below her chin and is easily twice as small as the right hand.
- Towards the end of the episode right after the babies eat the dog food you see Venus lick her lips, while Comet and the rest of the babies spit it out. Yet in the following scene Comet says the dog food tasted good, while Venus and the rest of the babies didn't like it.
- When Sputnik grabs Halley and Jet to take the picture her arms are extra long.
- There are a lot of extra shelves, and bookcases in the Vivian's kitchen, that do not appear again.