An ICreativeTabObject represents a creative inventory tab.

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import crafttweaker.creativetabs.ICreativeTab;

You can retrieve an ICreativeTab from the Creative tab Bracket Handler.

ZenGetter/ZenMethod	Return Type
ZenGetter/ZenMethod searchBarWidth	Return Type int
ZenGetter/ZenMethod tabLabel	Return Type string
ZenGetter/ZenMethod setNoScrollBar()	Return Type void (nothing)
ZenGetter/ZenMethod setNoTitle()	Return Type void (nothing)

Uses a string (e.g. "item_search.png").
Returns void (nothing).

ZenScript
 Copy
tab.setBackgroundImageName(String backgroundImage);