>>55702985>>55703002Meltan can only be evolved into Melmetal in pogo. Either can be gotten easily in Home for transferring anything from pogo, but shiny version is only obtainable in pogo during a specific FOMO event. Last one was about a year ago, you'll need to keep an eye on what's coming up if you want that shiny. Because we don't know when it's gonna be up.
Note that alongside kantomons, Meltan and Melmetal can be transferred to LGPE directly, omitting the transfer cooldown and letting you re-pick the ball.
Other than that? Vivillon patterns, in a way. Patterns are assigned to regions, if you connect to SV and send a postcard from that region, the corresponding pattern will appear on all Vivillon (and Scatterbug) in Paldea until midnight.
Alternatively you can get those bugs in pogo, but you'll need 3 postcards saved to spawn a scatterbug of a pattern, and then 124 candy to evolve one...
Pokeball pattern is unobtainable though
Another thing - coin form Gimmighoul, exclusive to pogo. Requires sending a postcard to SV.
If they count - mythicals and shiny mythicals. Some like Genesect and Darkrai can be caught in raids sometimes (shiny odds 1/20, like all 5* raids), some in free special research which will take a while (Mew, Victini, Celebi, Shaymin, Meloetta, Jirachi), some shiny mythicals from paypiggy masterwork tickets (FOMO + VERY long research - shiny Mew, Jirachi, Shaymin), some normal mythicals from other FOMO paypiggy events (Diancie, Keldeo, Zarude, incoming Marshadow).
BE WARNED that if you want to be able to send your pogo mythicals to games, you'll need to pull off a trick, let me know if you're interested, then I can explain it further.
Technically not pogo only but still worth knowing: shiny legendaries from raids (aforementioned 1/20 odds)
Think that's about it