Marigold

Marigold is a plant from Plants vs. Zombies and the little sister of Sunflower. Although she is obsessed with money, most of her comics focus on her coming out of her shell as a quiet and docile character.

Appearance
Per the series, Marigold is based off of her namesake, with a yellow face and squared-off petals, along with the standard four basal leaves. She also has a distinct single bucktooth, which appears to be purely a cosmetic issue.

Personality
Marigold is docile and quiet, lacking the energy of her older sister. Her interactions with Sunflower and Fume-shroom imply that they are the only individuals she feels comfortable perking up around. Her reserved nature may be the reason she owns a locked diary, since it is most likely the most reliable method of expressing her own thoughts.

Marigold is attracted to money and as a result has adopted penny-pinching habits. Unlike Gold Magnet, however, this is restricted to simply refusing to lend it and researching cost-efficiency. Coincidentally, the latter's more zealous stinginess has created a rift between the two.

Marigold is also highly capable of quickly reaching mutual understanding with others, making her an excellent fit for short fuses like Fume-shroom.

Fume-shroom
Fume-shroom is Marigold's closest friend. Her introversion also suggests that he is the only person she has formed a true bond with, and may explain some of her true feelings towards him - there are several hints that strongly imply Marigold is in love with him, though these feelings are not returned.

As mentioned above, Marigold's own personality keeps Fume-shroom's short temper in check.

Sunflower
Sunflower is Marigold's older sister; naturally, the overwhelming affection the former bears is returned by her. However, the sisters still maintain a natural sense of distance due to them maintaining opposite social aspects of their personalities.

The locked diary Marigold owns is also a source of unrest, as it essentially distorts Sunflower's view of her as a completely pure and innocent little girl to be protected.

Blover
Blover is, in Marigold's eyes, simply a friend of hers, though not as much as Fume-shroom. The two began interacting once Blover met Sunflower, leaving a particularly shallow connection. This is reinforced when Blover tries asking Marigold for money, only to tell him that he's on his own.

Issue 6: Fume-shroom's Sugar Rush
Marigold is seen trying to offer a cake to Fume-shroom, who kindly declines due to his hypersensitivity to sugar. When Fume-shroom somehow manages to lick the side of the cake while talking, Marigold is instantly killed by the resulting spray of fumes.

Issue 8: Dreadful Birthday
Marigold, being Sunflower's little sister, sets up a surprise party for her birthday, which quickly takes a turn for the absolute worst when Lawn Mower shows up. Strangely, Marigold is absent from the two panels showing the death of her sister.

Issue 12: Is It Love? Part 1
Marigold is the main protagonist of this issue, hanging out with Fume-shroom. When Red-point Tulip shows up, Fume-shroom suddenly leaves Marigold to ask the latter out on a date, leaving her alone and heartbroken. The end of the issue shows her crying in front of the horizon.

Issue 55: Love Letter
Fume-shroom hands Marigold an enclosed love letter, to which she is initially overjoyed at. Unfortunately, the letter inside is signed by Weed Gatling Pea, rendering her furious.

Issue 56: Rhyme Scheme
She introduces herself in a poem-like manner, just like the other plants, and stating herself to be a upholder of producing coins.

Trivia

 * For some strange reason, Marigold happens to attract plants who are older than she is, to the point of creepiness. The most egregious example would be Weed GP's case, who at best is a seventh grader writing to a fifth grader and at worst is an eighth grader writing to a fourth grader.
 * Her appearance resembles more of that of a common daisy rather than an actual common marigold
 * Her being a sister to Sunflower may be based on the two being flowers that produce a useful resource in the first game (sun and coins, respectively).