Vanessa Doofenshmirtz (2nd Dimension)

"Listen, Mom, Dad, come here. You guys, I'm only going to say this once...... (breathes for a second) ......... RUN!!!!"

- 2nd Vanessa showing her true colors.

2nd Dimension Vanessa Doofenshmirtz is a supporting antagonist of the Phineas and Ferb episode Tales from the Resistance: Back to the 2nd Dimension, the sequel to the 2011 TV film Phineas and Ferb The Movie: Across the 2nd Dimension. She is an alternate reality version of Vanessa Doofenshmirtz, but turns out to be as evil and intelligent as her parents 2nd Dimension Heinz Doofenshmirtz and 2nd Dimension Charlene Doofenshmirtz.

Just like her original counterpart, she was voiced by Olivia Olson.

Personality
Just like her original counterpart, 2nd Vanessa is very sarcastic and tends to act like a normal teenager as she seemingly has no interest in doing evil like her family and that she would rather have a social life to enjoy with. However, 2nd Vanessa revealed herself to be more sinister than her original counterpart as she is very loyal and caring to her parents, even proving to be quite intelligent and conniving as she managed to formulate a successful escape plan for her family in case they would face arrest for their crimes. She is also very manipulative, as she managed to deceive 2nd Candace into having a moment with her parents, which contributed to their escape.

Across the 2nd Dimension
2nd Vanessa made a cameo appearance in the TV film during the scene "Vanessa meets Doof", when she confronts her father (who is ruling their Tri-State Area with an iron fist and his army of Norm-Bots) for banishing another boy named Tony Marzulo for showing an interest towards her, warning him that she will never have a social life if he keeps this up. After her father makes a nonchalant reply to this, she notices another person standing next to her, but her father replies not to mind him, saying that it's just himself from another dimension. 2nd Vanessa then storms off to her mother's place, and takes her father's blimp to get there. 2nd Doofenshmirtz then tells 2nd Vanessa to tell her mother that she had fun though. This scene was cut from the film, though it was later shown in the movie's DVD through the bonus features.

Back to the 2nd Dimension
2nd Vanessa returned in the episode sequel, where she is seen staying at her mother's penthouse two months following her father's arrest and the Norm-Bots' destruction. She is aware that her mother had turned 25 of O.W.C.A.'s agents into ruthless cyborgs during their family's reign, similar to how her father turned 2nd Perry into Platyborg. She is also aware of the fact that her parents had filed a fake divorce to secure their finances and safety in case their reign would be overthrown. As 2nd Vanessa leaves the scene to seemingly go for a movie with Tony, little did she know that the Resistance are coming by to the penthouse to take her mother into custody by bringing in her captive father along.

After the Resistance freed all of the agents (except for Pandaborg) of their evil programming, their leader, 2nd Dimension Candace Flynn, is about to take both 2nd Doofenshmirtz and 2nd Charlene into custody by having the agents to hold them at gunpoint. Before the situation could get any crazier, 2nd Vanessa arrives back to the scene, demanding everyone to stop fighting at once. After going past through the reprogrammed agents, 2nd Vanessa convinces 2nd Candace to let her have a moment with her evil parents. However, this was revealed to be a trick, as 2nd Vanessa (proving to be as evil and intelligent as her parents and that she still loves them) planned for Tony to drive both her family and Pandaborg in a hover car to escape from Resistance custody, much to 2nd Candace's anger. As the notorious Doofenshmirtz family escape, 2nd Vanessa introduces Tony to her parents, and 2nd Doofenshmirtz recognizes him as the boy he once banished earlier, to which 2nd Charlene confirmed, stating that nobody actually saw it. It's completely unknown if 2nd Vanessa and her family were ever taken into custody or lived the rest of their days as fugitives.

Trivia

 * Similar to her mother 2nd Charlene, 2nd Vanessa is a rare point when a character is a neutral character in the original universe and an evil villain in the alternative universe (the closest villain to that point is Darth Ferb, but he is an evil counterpart of a main hero).