The LEGO Movie 2 Trailer: 7 Easter Eggs & References You Might Have Missed
4. Sewer Babies
A popular urban legend is that of sewer babies, who are unwanted children that get flushed down the toilets to live in the sewers, free from parental rule, and become feral.
A bit of an odd reference, but a parade of sewer babies pops up from a manhole cover as Emmet walks past. He wishes them a good morning, and they scream at him.
The babies are armed, and their weapons show a passing resemblance to the dwarves from the Hobbit franchise's LEGO sets - one has an axe, another a hammer, both very similar to those used by the dwarves.
However these are likely just re-used assets, with the babies added to emphasise the quirkiness of the setting.