There are many 'easter eggs' dotted throughout the game, most of which are based around popular culture and video games.
There a few 'easter eggs' that are linked to the Super Mario series of games, such as a poster which can be seen to say 'Los Super Hermanos' (the Spanish translation of 'The Super Brothers') with an image clearly imitating the style of Mario and Luigi. There is also a sequence of gameplay which is reminiscent of the final level of the first castle in the original Super Mario game. In this sequence Alebrije is dropped in to the lava after destroying a bridge with a large golden axe. This is in reference to Bowser being defeated in the Mario game in a similar fashion. The subsequent scene shows X'tabay saying "Your princess in another castle" which is a direct copy of what Toad says after Bowser is defeated. There's also a brick outline of the NES Mario in Santa Luchita, and a riff of the Great Temple music is the Mario "underground" theme.
There is also an easter egg linked to the popular indie game 'Minecraft' where the mining shop has a pixel art pickaxe above the door which is stylistically similar to those found within Minecraft. In the Dead World, this building is called The Nether Portal
In the opening town, there's a poster which advertises a fight between a wrestler wearing Majora's Mask, from the Legend of Zelda, and the "Mega Hermano", who wears blue including a helmet--Mega Man.
Legend of Zelda gets another call in a the stained glass of the church and yet another sign in Santa Luchita--a poster advertising a wrester with a pointed green mask, Las Linka.
In Santa Luchita Dead World there's a poster advertising a fight between Batman and Bane.
There is also posters that say "los casa crashers" referencing the game "Castle Crashers"
There is another poster saying "Bust it Bill" referencing the movie "Wreck it Ralph"