Regarding the -eł postfix used in Polish doge meme (pieseł) - it's not obvious to everybody in Poland, but most young people know it's "Jewish-like".
It was formed as a variant of mamełe/tatełe. It was a funny way to refer to your parents popular on some social media in Poland, and these ones are universally recognized as Yiddish influence.
It comes not from meeting Yiddish speakers (because there are effectively 0% chance of meeting one in Poland), but from people trying to make word jokes basing on media and Jewish humor.
Pieseł had been first used and popularized by Michnikowski in cabaret first in 60-ties. At the time there was still enough people in Poland who were either speaking Yiddish or familiar with the language from before the war.
Like my father who spoke good German but also had daily contact with Yiddish on the street [4] before the WW2 as a (Polish) kid in Wola. This type of pieseł jokes and many other Michnikowski performances had its public in Warsaw at the time.[1] [3]
[4] My father had been 10 years old in 1939. In Wola - workers district (read poor) Jews and Polish lived together mixed and only Kiercelak (large open air market with many Jewish merchants and tradesmen) separated Wola from Nalewki (nominaly Jewish district). It is all walking distance especially for 10 years old so you have heard Yiddish (and Yiddish mixed with Polish) every day.
It was formed as a variant of mamełe/tatełe. It was a funny way to refer to your parents popular on some social media in Poland, and these ones are universally recognized as Yiddish influence.
It comes not from meeting Yiddish speakers (because there are effectively 0% chance of meeting one in Poland), but from people trying to make word jokes basing on media and Jewish humor.