Vanessa Doofenshmirtz (2nd Dimension)

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

- 2nd Vanessa showing her true colors and loyalty to her family

2nd Dimension Vanessa Doofenshmirtz is the daughter of 2nd Dimension Doofenshmirtz and 2nd Dimension Charlene, making a cameo appearance in Phineas and Ferb: Across the 2nd Dimension, and later becoming the secondary antagonist in Tales from the Resistance: Back to the 2nd Dimension. She is an alternate reality version of Vanessa Doofenshmirtz, but unlike her parents (who both have a differentiation in personality from their counterparts), she happens to retain the same personality and mannerisms as her original counterpart, though there may be a few differences between the two.

Like her original counterpart, she is voiced by Olivia Olson.

Across the 2nd Dimension
2nd Vanessa first appears in the TV film during the scene "Vanessa meets Doof", where she confronts her father (who is ruling the 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. She then notices another person standing next to her, asking who is he. Her father replies not to mind him, saying that it's just him from another dimension. 2nd Vanessa then storms off to her mother's place, and takes her father's blimp keys to get there. 2nd Doofenshmirtz then tells 2nd Vanessa to tell her mother that she had fun though. This scene was actually deleted from the finalized version, though it was later shown in the movie's DVD through the bonus features.

Tales from the Resistance
2nd Vanessa returns 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 is just as evil as her father, since 2nd Charlene had turned 25 of O.W.C.A.'s agents into ruthless cyborgs during 2nd Doofenshmirtz's reign, similar to how 2nd Doofenshmirtz turned 2nd Perry into Platyborg. She also might be aware of the fact that both her parents had pretended to be divorced to gain several advantages (such as tax records, separate vacation trips, and junk yard sales). As 2nd Vanessa leaves the scene to 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. While a freed 2nd Doofenshmirtz and 2nd Charlene attempt to battle against the kids, the Resistance freed the agents of their evil programming, and 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. However, 2nd Vanessa arrives back to the scene, demanding everyone to stop fighting. 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 somewhat evil and intelligent like 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.