It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.entity.IEntityFishHook;

IEntityFishHook extends IEntity. That means all functions available to IEntities also are available to IEntityFishHook.

ZenGetter	GetterMethod	Возвращаемый тип
ZenGetter caughtEntity	GetterMethod caughtEntity()	Возвращаемый тип IEntity
ZenGetter angler	GetterMethod getAngler()	Возвращаемый тип IPlayer

Сеттер	SetterMethod	Parameter Type
Сеттер lureSpeed	SetterMethod setLureSpeed(lureSpeed)	Parameter Type int
Сеттер luck	SetterMethod setLuck(luck)	Parameter Type int