Tish is considered the smart one of the group, being skilled in a wide variety of arts and sciences. She usually speaks and expresses her opinions in a factual or literal matter, seldom hesitates to correct her friends, and often backs up her opinions by quoting famous people in history, most often of her idol William Shakespeare.
Tish has a tendancy to be a perfectionist, often freaking out over minor mistakes or miscalculations in her data, but none-the-less carries herself with a high degree of self-confidence and assurance. Despite often being teased by her friends about her intellect, lack of athletic abilities and obsession with academics, she is respected and appreciated by her friends to an extensive degree, and for the most part willing to accompany them on their countless adventures. Tish's intellect and responsible persona cause her to act as the group's "voice of reason". However, she is seldom listened to, which often frustrates her.
Tish spends the majority of her life with her four friends, but is probably the most different from them in terms of hobbies and past-times, one of the most distinct being the fact that she is a vegetarian.
Tish's main life's passion is intellect, which she often uses to either assist, change the opinions of, or annoy her friends. It was originally Tish's idea to make the museum a common hang-out spot for her friends, although they were initially opposing of this idea. However, her friends have grown to like visitng the museum and other intellectual locations almost as much as she does.
Desptie being one of the two female members of the group, Tish and Lor have rather opposing personalities and interests. While Lor is athletic, tomboyish, and has an interest in sports and virtually any type of vigorous activity, Tish is more laid-back, lacks athletic skill, and tries to distance herself from activities involving physical contact, fast movement, balance or speed.
Tish has a wide variety of interests in the arts. Throughout the series, Tish has shown a passion for sculpting, painting, pottery, poetry, noveltry, history and theatrical productions. Although her friends sometimes find this trend weird, they are quite accepting of it, and often accompany Tish during her activities of choice.
In Taking Sides we learn that Tish sometimes love to play dress-up.
During season 1,2 and half of 3 Tish was the only character in the group not to have a crush on someone, until in "An Experimental Weekend" where we are introduce to Dr.Skippy and is shown to be her crush, he also appeared in Tish's fantasy in "celebrity"
In "Brain Dead" her name Petratishkovna means Girl with 1 nose.
Tish's name is potentially a play off of The Tisch School of Arts, part of the New York University.