Here I'll show you some ideas I had regarding the textures of blocks and mobs in 1.19:

 

 Let's start with the mobs:

 

 -Warden: Warden could have the texture of the larimar corrupted, being a gigantic and frightening ice monster.

 

 -Allay: The allays could have the texture of Aquamarines that appear in homeworld in steven universe.

 

 -Frogs: Frogs could have the texture of the frog that appears in the Steven Universe episode "The Answer".

 

 Now let's talk about Ancient city's:

 

 Skulk Shrieker: This block could have the texture of a "Pearl Duplicator Wands" table, as the sculk sensor contains the texture of the "Gem Stabilizers" table from Peridot's ship.

 

 *Sculk vein and sculk block: It could have the "vacuum" texture we saw in the episode Rose's Room.

 

 *Sculk catalyst: Could have the texture of the handcraft Peridot control table, to match the texture of the sculk sensor.

 

 *Reinforced deepslate: May have its texture inspired by the time pyramid core from the episode "Steven Too Serious".

 

 Now finally let's talk about the Mangrove Biome:

 

 We can transform the mangrove biome into the forest that we found in the episode "why so blue? - Steven Universe Future", having the mud that we see in this episode, accompanied by the blue trees and pink propagules.

 

 - Mangrove trees: It may be the blue trees that we find in this Forest that have blue roots too, in addition to the woods and their variants having bluish tones.

 

 - Mud: it could be the same one we see in this forest in a reddish tone.

 

 -Clay bricks: their textures can be the same as those of sand glass sand constructions.

 

I apologize for the spelling mistakes, I'm Brazilian and I use the translator to translate to English.