SCP Foundation

So, skimming quite a few articles like 035 or 079 it shows that these anomalies do know each from some time or place, a few pairs I theorized about due to their very similar style in looks and psyc.

049 & 035: These two seem to have a lot in common with their attitude and wit, both of these items are coming into existence probably during the 14th to 17th century and just are so similar in just so many ways to count.

076 & 073 "Cain and Abel." Don't think this one needs explaining.

All of the broken god SCP's: Again this one is pretty obvious.

173 & 096: Both anomolaus effects rely on the interactants vision.

Dr. Bright/The Duckman/whatever moniker he currently prefers (Batman?) has declared that all of his skips are connected; his avatar has several siblings in containment cells.

Metaphysician likewise created his own neat mythos, as did Fantem with their Sarkic and Pitch Haven (respectively) series.

SCP-2273 was built in a parallel universe by SCP-1000; SCP-2932 was also built by SCP-1000, but in main Foundationverse.

AstronautJoe always included references to "Pattern Screamers" in his work, implying connection between them, and Kate McTiriss always wrote about stuff happening in Florida. So yeah.

I might just point out that sandrewswann also has his own mythos of connected SCPs - the "He-Who-Made-Dark" series, presently consisting of SCP-286, SCP-319, SCP-435, SCP-719, SCP-1736, and SCP-1806.

Skara Brae also has the Bonifay series, consisting of SCP-1890, SCP-1896, and SCP-1928.

SCP-1193 and SCP-1877 are the same phenomenon, viewed from different angles.

SCP-1348 and SCP-1427 were created by the same culture. SCP-1115 was created by someone else, but I meant to subtly imply that the same culture was responsible for that as well.

Roget has this Class of '76 series, consisting of the SCPs SCP-1423, SCP-1833, SCP-332, and SCP-814, and the tale series Remembrance.

Also, search beryllium bronze (or just beryllium) and see how many links come up. (seriously, there's like a whole myth arc that is just about beryllium bronze.)