Custom textures in Doom Builder 64

how or even if it's possible to port this lava texture to DB64

Put it between TT_START/END markers. It won't animate though. Not sure if it is possible to define new animations.

I could be wrong, but isn't it possible to get any texture to animate in db64? IIRC 'animation' is just 2 static textures scrolling diagonally across each other to achieve the effect

That's the "liquid effect" sector setting. It does that, however other textures are animated like classic Doom style (a set of textures). Although some in Doom 64, like the lava texture, uses palette changes to animate. I don't know if EX supports adding new animated textures in this format.

thank you all for the help!

You guys never bother Googling do you?

http://doom64ex.sourceforge.net/wiki/index.php/Adding_Animated_Textures