Red Chaser

They were just added to us pal egg machine

Just pulled one from the Pal Egg Machine as well. Guess that's one less low cost/rarity monster to farm.

They are? Nice! I can actually get a chance at beating Gaia!

Chasers and Pirates are nao available in da PEM.

This is a variation of the gambler's fallacy..

The invade rate will be 4% (or whatever) every time, regardless of how many times you run the dungeon. Previous attempts do not create a higher likelihood of success.

You could, therefore, run the dungeon for a million years and never get it.. lol. Though in practice, it's probably not that bad. Just don't be surprised if, for example, you run "Flame Snake Woman" for what seems like eternity, only keeping up hope because the people online insist a Naga will drop eventually. (On my new account I've been running it about five or ten times every day or so for a couple weeks.. I think on my old account I got it @ around 12-15)

Not replying to you in particular seeing how this is late, but just posting this up for others in case they have the same question.

First of all, invade rate for anything appears to be higher on the harder difficulties. Seeing how Expert is considered a "low" difficulty you shouldn't expect to see anything on it.

Second of all, 10 times without a show isn't really special if the invade rate is 4%. It's basic math. That means around 25 runs for one of these guys. 10 isn't even half of that.