Tips on how to successfully introduce a (seemly) aggressive rat?

[Imitationangel]

A month ago I got a new rat to be cage mates with mine, after his original cage mate unfortunately passed away. They're about half a year apart in age. but whenever the newer one (Tobias) sees him (Megi) he goes all "crazy" in his cage and starts frantically scratching at the bars :/. So much so I'm nervous to let them out together. I don't have a bathtub, which I know is something a lot of people use as neutral ground, but I do have another room and playpen that Megi has never been before. I'm just so worried Tobias will hurt him, and I don't want to stress either of them out . The previous owner of Tobias had him in a cage with 12+ rats due to an accidental pregnancy and has said she never had a problem with him fighting. I'm not sure if he even would, maybe that's just him being excited, he doesn't puff up or breath oddly when doing it and I've never experienced anything like it. Any knowledge shared is help and greatly appreciated (I can upload a video if it would help!)

 

[SQ]

You might want to check out the info at joinrats.com to see if any of it fits your situation.
There is also this thread on intros https://www.ratshackforum.com/threads/introducing-new-rats.34842/

yes, a video would be very helpful

 

[jorats]

It's been my experience that how rats react to each other between bars is not at all how they react during intros. I like to do my intros on table tops. They are high off the ground, they are in the wide open with no place to hide. I place some yummy treats in the middle, wet food so they are forced to stay close to each other while eating it. Start with just 15 minutes like that. And continue to do intros like that daily. If you can do several 15 minutes sessions a day, that would be good too.