All the assets used to make the OURPLE GUY office in Frickber's 3.

To manually add these to your game, install UndertaleModTool and import the sprites to there respective places.

BEAR IN MIND: This method of modding can reveal spoilers for content in the game through texture groups alone, so I can only recommend doing this if you have already completed all the endings.

Open up UndertaleModTool and go to "File", click "Open", and select the data.win for the current version of Frickbear's 3.

Under "Data" click the arrow nest to where it says "Sprites" which will reveal all of it's contents.

You can easily search for the correct sprites by typing where it says "Filter by name..." (I'd recommend typing out "sOffice" since most of the assets for the office use that prefix)

Double click the asset of your choosing to reveal it's associated sprite, then double click the Texture PageItem. (if it's an animation/collection of sprites there will be more than one PageItem to change)

Now you can click "Import" and select the file you want to replace with it. (all the sprites in the folder use the same names as the ones in the code to make things easier)

And that's it, enjoy the mod!