Right click Stellaris in your Library

Go to Properties -> Betas

Switch to 2.6.3 in the dropdown (probably says None for you) and wait for it to install

Make sure to play on Iron man you dweeb! My game settings were reset when I switched versions.

Do a Federation Xenophile start on cadet for 2 free species and extra envoys (you can get more by leveling up your Federation while you're waiting on your neighbors to text you the first time). If you get a crap starting layout for Federation just reset (like if you're backed into a corner by your allies).

Use envoys and 10 minerals/30 years trade deals with everyone to make friends and get migration treaties.

Take Expansion for 2 starting colony pops, then use your migration treaties to create colony ships, which you can use to spawn different pops on planets (habitability really doesn't matter).

It helps if you spawn next to some Driven Assimilator dweebs with a bunch of unused planets you can take without having to wait on influence (just about the only time I enjoyed spawning next to them). You can also buy different poke-nerds off the Slave Market once the Galactic Market is established.

Collect 10 different poke-nerds, switch your resettlement Policy to allowed, then resettle one of each to your Pokemon Center gotta-catch'm-all planet of choice. I didn't test with sub-types or robots, I'm assuming they're probably finicky.

Collect achievement, then switch back to the main build (Don't forget to do this as, 2.6.3 had a bunch of obnoxious bugs. The 1000 food 4 pop growth planetary decision was dope though).

I just saved you googling 14 different threads with bad voodoo information and digging into bug reports.