The videos below, don't even stop there. One thing Konami is famous for, is putting cameo appearances of their own characters in different games. Ganbare Goemon 2, Mitsumete Knight R : Daibouken Hen, and Scribblenauts are just three examples of games that have characters from other games within them. I'm sure you likely know even more examples than that, so why don't we start with a visual challenge.
Mitsumete Knight R : Daibouken Hen is one of the biggest examples I've seen so far that shows off multiple cameos of characters from various Konami games. If you want to see if you can guess most or all of them, do it right now.
Otherwise here is a spoiler alert for a list of every single one of them. Taken from the YouTube video post that has them listed of course.
* Goemon (ゴエモン) and Ebisumaru (エビス丸), of the "Gambare Goemon" series
* Vic Viper (ビッグバイパー) and a Moai head, of the Gradius series
* Shiori Fujisaki (藤崎詩織) and Saki Nijino (虹野沙希), of the Tokimeki Memorial series
* Twinbee (ツインビー) and Madoka (マドカ), of the Twinbee series
* Takosuke (タコスケ) and Koitsu (コイツ), of the Parodius series
* Kewne (キューン), of Azure Dreams
* Powerpro-kun, (パワプロくん), of the Jikkyou Powerful Pro Yakyuu series
* Alucard (アルカード), of Castlevania : Symphony of the Night
* The Main Protagonist, of Suikoden 1.
Yeah......take that in for a minute.
Are you back from the visual challenge yet? Cool. The second is really a no brainer at all. Even if you have never heard of the Ganbare Goemon series, then surely you have heard of Castlevania. For real, it's Goemon versus Dracula! They even included a small segment of Castlevania music just as Dracula emerges from a bat.
The third video shouldn't be too hard to guess. You may have heard of the game Scribblenauts. This is a cute Konami game that has multiple cameos of characters within its game as well. They are old Solid Snake and Big Boss, Alucard from the Castlevania series, and finally Ganbare Goemon once again. Goemon is also known as Mystical Ninja to some parts of the world. There are a number of other examples just waiting for you to check out.
YouTube is a breeding ground for them obviously. So which cameo video is your favorite? Personally I'm quite a fan of the Ganbare Goemon series. I just wish they would get translated or released again with English text.