She was a crucial part of the group's Halloween costume as a member of the Justice League. Ultimately, Penny would go all-in with the attire even dawning the black wig.
The result was definitely a not so PG look, one that all comic book fans would never complain about. Who did it better, Kaley or Gal Gadot?
We saw this on more than a couple of episodes, Penny dressed up in a not so PG outfit in order to entice her man – that's a common thing not only on the show but in real life, too – who doesn't appreciate their partner dressing up and adding excitement into the relationship?
Penny definitely achieves that with the outfit.
Out of 12 seasons, this scene remains among the most iconic. While in the laundry room, we saw some memorable moments featuring both Penny and Sheldon.
This one ranks up there because of the not so PG twist – one that saw Penny take it all off, while Sheldon watched on uncomfortably.
Sheldon was confused as to what Penny could have provided by showing up during this particular scene – Leonard would then tell her to take it off – a moment that would reveal Penny in a not so PG dress.
Even Raj just couldn't seem to look away and seriously, we can't blame him.
This scene definitely kicked things up a notch in terms of the not-so-PG nature. We assume CBS cringed a little at the scene, showing Penny revealing a little bit too much, while Leonard was also wrapped in minimal clothing as well.
For some viewers at home, this was like a fantasy come to life...
This one really isn't an outfit but instead, really just a towel wrapped around Penny. This photo comes from the earlier seasons – Penny's shower broke so she requested using Leonard and Sheldon's.
We can say that Leonard's love for Penny started around this point and it would only snowball in the next episodes – all the way till the end.
Popular Big Bang star Will Wheaton also took part in this scene; he was totally covered up in a costume.
As for Penny, well, clearly the opposite holds true as she appears to be looking more than a little steamy. Had the scene lasted a little longer, maybe CBS would have sweat a little bit more.
Another iconic scene, Sheldon knocking on Penny's door three times; the result was usually a bad exchange between the two (which made for great TV).
In this scene, Penny answers the door in a not so PG outfit, it was way too early for Penny as Sheldon asked for a lift.
At this point, the bond between Leonard and Penny started to intensify. Leonard was also starting to stand up for himself, even if it meant potentially getting his butt kicked by Penny's massive ex-boyfriend.
The not so PG cat outfit definitely helped Penny's cause – it was only one of the many times she would play dress up in a costume throughout the course of the show.
Fans exhaled during this season as Penny completely altered her look. It took some time to get adjusted, though most of us can agree she pulled the look off and then some.
In the photo above, Penny is alongside Leonard as they share some pillow talk. Fans, however, might've been too busy staring at Cuoco's night-time outfit of choice.
Even during the final episodes, Penny kept up with the provocative outfits.
Most fans might not know, but Penny almost got her own Charmed spinoff, which might've meant passing on Big Bang... Thankfully, it all worked out in the end.
Cuoco grabs our attention with yet another stunning black dress. She did that a lot throughout the show's 12 seasons. This particular dress compliments some of her best assets.
Maybe CBS should have made this episode rated TV-14? It's definitely not an outfit suitable for a younger audience, but hey!
This photo comes from Penny's earlier days on the show. She actually grew to stardom on a different network with ABC on 8 Simple Rules. Cuoco thrived in the role even if the show didn't last as long as expected.
Her stock would reach new heights during Big Bang – we can't imagine anyone else in the role of Penny.
Believe it or not, Penny's first love was actually tennis – she took on the sport at the age of three.
We can safely say that she made the correct decision, becoming one of the most iconic sitcom stars of the 2000s.
The bikini that turned everyone's heads. This might be the most iconic not so PG outfit ever rocked by Penny during the show's run. It was a new look for Penny, especially with her new head of hair as well.
