2nd Dimension

The 2nd Dimension (not to be confused as the other 2nd Dimension from the UnAnything Wiki) from the Phineas and Ferb multiverse (a.k.a. Heroic Candace's universe) is the most infamous and less popular dimension ever discovered, In 2015, it became part of the Un-Multiverse and a source of Youtube Poops/ YTP. This dimension is now became infamous, less popular and least favorite and also as a place where Dan Povenmire and Jeff "Swampy" Marsh hid their 2nd Dimension stuff and used it only as a Phineas and Ferb movie and an story arc episode and abandoned it after they make an series finale and a stand-alone episode of Phineas and Ferb.

In the beginning, Danville of the 2nd Dimension is ruled by 2nd Dimension Doofenshmirtz and his family (Charlene-2 and Vanessa-2),

However, Doofenshmirtz-2 and Charlene-2 became divorced, and all of the animal agents (including Perry-2) got captured and turned into ruthless cyborgs. There is a group called the Resistance founded by 2nd Dimension Candace sometimes.

This is where the Phineas and Ferb cartoon happens. There are few moments where another dimension is seen or mentioned, most notable is in Phineas and Ferb The Movie: Across the 2nd Dimension. The only observable difference between it and the second dimension is that in the first dimension First dimension Doofenshmirtz never lost Choo-Choo, that making him less evil, so that he never took over the Tri-State Area. But now that 2nd dimension Doofenshmirtz found Choo-Choo and lost his "true evil", these two dimensions could be almost the same again. But in 2015, The 2nd Dimension's existence started to get berserk, haywire, retarded, and horribly wrong. Now became a famous place for video game bootlegs

Phineas and Ferb The Movie: Across the 2nd Dimension
The 1st Dimension people (Phineas, Ferb, Candace, Agent P, and Doofenshmirtz) first appeared in the 2nd Dimension. Doofenshmirtz-1 were having a conversation with his 2nd dimension counterpart of him about his backstory about losing his toy train named Choo-Choo. Phineas-1 and Ferb-1 met their 2nd Dimension counterparts, and discovered that 2nd Dimension Candace is the leader of the Resistance, Candace-1 appeared the 2nd Dimension and met her 2nd Dimension counterpart. But then they went to Doofenshmirtz-2’s fortress and it was a trap. But then tried to escape from the hands of the Normbots, but Candace-2 separated the mine carts to sacrifice the 1st Dimension Phineas, Ferb, Perry, and Candace. But then Doofenshmirtz-2 forced Phineas-1 to fix the machine, but self-destruction is the answer. So Doofenshmirtz-2 sended the 1st Dimension Phineas, Ferb, Perry, and Candace, at THE DOOM! and betrayed his 1st Dimension counterpart too. At THE DOOM! Phineas-1 and Ferb-1 and the 1st Dimension gang were sent to be eaten by Goozim. But Candace-2 appeared to let the 1st Dimension gang get back to their home dimension as another chance. Doofenshmirtz-2 begin to takeover the 1st Dimension Tri-State-Area. But then got defeated by Phineas-1 Perry-1, and Ferb-1, and his true evil got really melted by his 1st Dimension counterpart giving him his Choo-Choo. Now Phineas-1 and Ferb-1 saved Danville of the 2nd Dimension and their Danville of the 1st Dimension. The two dimensions could be the same. (Phineas and Ferb The Movie: Across The 2nd Dimension)

Tales From the Resistance: Back to the 2nd Dimension
But, however after two months passed and Danville-2 is still half between the 1st Dimension and Doofenshmirtz’s reign as a hybrid dimension, a new threat appeared at Danville Park-2 that it was two giant robot ants and a couple of animal cyborgs has kidnapped Perry-2. The threat was Doofenshmirtz’s ex-wife Charlene, who was planning to capture the Resistance and turn them into ruthless cyborgs too. After Phineas-2 and the Resistance rescued Perry-2, Phineas-2, Perry-2, and Candace-2 headed to Charlene-2’s large penthouse to stop her, but Charlene-2 turned Ferb-2 into a cyborg, However, she threw Doofenshmirtz-2’s Choo-Choo away to make Doofenshmirtz-2 get his true evil life back, then, Ferb-2 disguised himself as a cyborg, letting his stepsiblings free, because of Phineas-2 planned to make a frontal attack into Charlene-2's penthouse to rescue all of the animal cyborg agents and stop Charlene-2 and Doofenshmirtz-2, but however happened, Vanessa-2 tricked the Resistance to retreat with her parents and her boyfriend Tony Marzulo gave the Doofenshmirtz Family-2 a ride.

Despite to the Doofenshmirtz-2 family's escape. The Resistance did rescued the animal agents from their evil programming (except Pandaborg that Ferb-2 didn't used the hats to remove the animal cyborg agents’ evil programming). But now, Candace-2 let the rescued animal cyborg agents to take the Resistance’s place to track down the Doofenshmirtz-2 family. Now, Candace-2 began to have a date with Jeremy-2. (Tales from the Resistance: Back to the 2nd Dimension)

End of summer
At the end of summer after the 1st Dimension’s time has been straighten (Last Day of Summer episode of Phineas and Ferb) Candace-2’s brothers betrayed her and Doofenshmirtz-2 and ruled Danville-2, Candace-2 is now stuck busting her brothers and started to tell her 1st Dimension counterpart to help her bust her brothers and free Doofenshmirtz-2 and Charlene-2 out from her brothers hands. Unfortunately, her stepbrother Ferb-2 began to warn Candace-2 that Phineas-2 planned to eliminate her. Candace-2 and her counterpart and Doofenshmirtz-2 and Charlene-2 began to put a stop to her brother’s evil plan. Finally Candace-2 busted her brother and he ran away nowhere to be seen. (Candace and the Return of the 2nd Dimension fanfiction)

After the series finale
The Resistance got banned and disqualified and disbanded after Candace-2 was found guilty of her protection with her brothers went wrong. A 2nd Dimension counterpart of Milo Murphy lived in Danville-2 suddenly, he has a ability (named Murphy's Law) to spread disater, dispare, disorder, mayhem, chaos, and bad luck to anyone and anything. During his school days, Danville-2 started to screw up and were starting to get haywire, retarded, berserk, crazy, and went 100% horribly wrong. Now Danville-2 and the Tri-State-Area-2 collasped and became a post-apocalyptic-wasteland, thanks to Milo and his family now got kicked out from Danville-2 and everyone in Danville-2 became homeless that they began to move to a new home and new state. The Flynn-Flecter Family-2 began to move to a new city and state when needed a new life, except Candace-2. Candace-2 felt mad and began to turn her Resistance allies into cyborgs and built a Resistance edition of Doofenshmirtz-2’s Normbots to rule Danville-2.

In 2016-present, Danville-2 is now inhabited by Pokémon from another world. A group of creepy aliens known as The Shroob Army-2 led by Princess Shroob-2 appeared to rule Danville-2. The Kraang (Kraang Prime/Subprime) from Dimension X came to this dimension to find some places to make their secret bases.

It turns out that this dimension is a rip-off of the other 2nd Dimension