Who created the original Minecraft textures, before 1.14?

The game was solely developed by Markus "Notch" Persson, all the way up to the creation of Mojang, where others (primarily Jens "Jeb" Bergensten) took over as lead designer (emphasis mine):

The original edition of Minecraft, now known as the Java Edition, was first developed in May 2009. [...] The base program of Minecraft was completed by Persson over a weekend in that month and a private testing was released on TigIRC on May 16, 2009. The game was first released to the public on 17 May 2009 as a developmental release on TIGSource forums. Persson updated the game based on feedback from the forums. This version later become known as the Classic version.

[...] Persson continued to update the game with releases distributed to users automatically. These updates included new items, new blocks, new mobs, survival mode, and changes to the game's behavior (e.g. how water flows). [...]

Mojang moved the game out of beta and released the full version on 18 November 2011. On 1 December 2011, Jens "Jeb" Bergensten took full creative control over Minecraft, replacing Persson as lead designer.

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