Much like Cuddles, Giggles, and Lumpy, Petunia seems to be friends with many of the show's characters, with a few exceptions here and there.
While they haven't directly interacted, Petunia most likely knows Cuddles as Giggles' boyfriend and has been on a few trips with him, as seen in From A to Zoo and Take a Hike. Cuddles and Giggles both went to the burger joint that Petunia works at in Flippin' Burgers. They also volunteered to help fix Giggles' house in Home Is Where the Hurt Is.
- Main article: Petunia-Giggles Relationship
Giggles is Petunia's best friend in the show, they are seen doing many things together such as having tea parties, lunch, or simply hanging out together.
Petunia appears to be friends with Toothy. Their main interaction would be in From Hero to Eternity, in which the two were shown building a snowman. They also played Hide and Seek with Flippy and Flaky in Hide and Seek, and have been on trips with Lumpy. She is also seen playing see-saw with Toothy in one of the TV Series intro pop-ups.
Lumpy has been shown to be friends with Petunia. In You're Bakin' Me Crazy, he attends her birthday party. In Wipe Out! she swoons over him, and Lumpy takes care of her along with the other characters in certain episodes.
- Main article: Handy-Petunia Relationship
Handy and Petunia have had some romantic experiences throughout the series. They fall in love in I Nub You and go on a date in My Better Half. Handy also built a tree house for Petunia in their debut.
Nutty has had very few interactions with Petunia. The first of these was in Take a Hike, where, after they became lost and thirsty, Nutty became annoyed at her moaning (This being one of the few times Nutty is the annoyed one, rather than causing annoyance to others).
In the False Alarm episode, Nutty killed Petunia through an accidental hit-and-run. At first he seemed concerned and even shocked at what he did. However, he immediately forgot after her internal organs formed Tetris-shaped blocks on his windscreen and began to "play".
It can be assumed that Sniffles and Petunia are friends. They appear on many trips together (From A to Zoo, Take a Hike, and Camp Pokeneyeout. Petunia is clearly horrified to witness Sniffles drowning in Mime to Five. She also tends to Sniffles as a nurse in Dream Job.
Petunia's main interaction with Pop occurred in Read 'em and Weep. As a girl scout, Petunia offered some cookies to Pop, until being attacked and killed by The Demon. They both also held hands together in Class Act.
Not counting the episode mentioned above, the only time so far where Petunia and Cub interact is Cubtron Z, in which Cub (or rather, Cubtron) killed Petunia, Giggles and Cuddles by using their bodies like crayons. Also, Cub waved to Petunia in Hello Dolly, probably because Cub is a child who likes meeting new people.
Flaky and Petunia seem to be on good terms. They have played Hide and Seek with Flippy and Toothy, visited Lammy for a game of poker in Royal Flush, sat together in the same cart on a roller coaster in Double Whammy Part I, and went on trips together in two episodes.
Petunia's only interaction with The Mole occurs in Pitchin' Impossible, where she seems confused as to why The Mole would want to play in the pitching game.
- Main Arcticle: Disco Bear-Female characters Relationship
Much like Giggles, Petunia is shown to dislike Disco Bear, perhaps even to a greater extent. Despite this, Disco Bear was somehow able to get Petunia to go on a date with him in Blind Date though she clearly regretted this.
Like most characters, Petunia dislikes Lifty and Shifty. The twins held her and Giggles hostage while taking over their lemonade stand in Gems the Breaks.
Petunia and Mime may have a crush on each other, as shown in I Heart U, and Easy Comb, Easy Go. A possibility may also lie in Who's to Flame?, in which Petunia invites Mime and Giggles to her house for breakfast.
Flippy and Petunia are shown to be friends, but they only interact in two episodes. In Hide and Seek, they are shown playing hide-and-go-seek, along with Toothy and Flaky. In Flippin' Burgers, Flippy may like the food at the restaurant Petunia works at, if it wasn't his first time there. However, she is not present at Flippy's birthday party in Party Animal, which means they are not that close.
Splendid has tried to rescue Petunia on several occasions, all with unsuccessful results. She may be a fan of his, as Wrath of Con may suggest. In that episode, she and Giggles were pleased when Splendid recharges Giggles' light saber. However, she didn't seem to want to attend his speech. In Just Be Clause, they interact again when Splendid bursts into her house as Santa. Splendid gives her a coal ring and crushes it to make a diamond. He also crushed Petunia's hand in the process but she doesn't seem to mind as she is happy with her gift.
Petunia was the first character to meet Lammy in A Bit of a Pickle in which they set up a tea party. When Lammy saw Mr. Pickels strangling Petunia she quickly tried to stop him only to end up strangling Petunia herself. Lammy later invited Petunia and Giggles to her house for lunch and poker in Royal Flush.
Mr. Pickels appears to dislike Petunia as he does with every character apart from Lammy. He attempted to kill her in the two mentioned episodes above, with Lammy unwittingly finishing the job.
- Russell is the only character Petunia has yet to interact with.