I can't make flying mobs!

Status
Fixed
Issue description

I wanted to make a mob in the End which flies and attacks the player, so I set Flying and made everything to make it attack me, the only thing which happened is an error! Then I wanted to make him only fly and nothing anymore, and I got an error! Please fix it, because I really can't do any flying mob...

 Gradle log:

Executing gradle command: build
Microsoft Windows [Version 10.0.16299.547]
(c) 2017 Microsoft Corporation. Alle Rechte vorbehalten.
C:\Pylo\MCreator173>cd forge
C:\Pylo\MCreator173\forge>SET "JAVA_HOME=C:\Pylo\MCreator173\jdk64\"
C:\Pylo\MCreator173\forge>SET JAVA_EXE=%JAVA_HOME%\bin\java.exe
C:\Pylo\MCreator173\forge>SET PATH=%JAVA_HOME%\bin\;%PATH%
C:\Pylo\MCreator173\forge>gradlew -Dorg.gradle.jvmargs="-Xms625m -Xmx2048m" build
To honour the JVM settings for this build a new JVM will be forked. Please consider using the daemon: http://gradle.org/docs/2.0/userguide/gradle_daemon.html.
Etag download for http://export.mcpbot.bspk.rs/versions.json failed with code 400
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:downloadClient SKIPPED
:downloadServer SKIPPED
:getVersionJson
:extractUserDev UP-TO-DATE
:mergeJars SKIPPED
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:downloadMcpTools SKIPPED
:extractMcpData UP-TO-DATE
:genSrgs SKIPPED
:deobfBinJar SKIPPED
:compileApiJava UP-TO-DATE
:processApiResources UP-TO-DATE
:apiClasses UP-TO-DATE
:sourceMainJava
C:\Pylo\MCreator173\forge\build\sources\java\mod\mcreator\mcreator_enderGhast.java:92:compileJava FAILED
: error: incompatible types: EntityenderGhast cannot be converted to EntityCreature
         this.tasks.addTask(6, new EntityAIWander(this, 1.0D));
                                                  ^
BUILD FAILED
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error
Total time: 13.965 secs
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
C:\Pylo\MCreator173\forge>
Task completed with return code 0 in 14364 milliseconds

Issue comments

Yes, the first attempt I wanted to make it agressive, like Ghast, but when the error happened I tried to make it only fly, and I got an error. After this I didn't put AI but It didn't move... Maybe I should put AI based on?

Thanks! But, there is a small but very good, I think, suggestion, make possible on new MCreator versions a "switch" between procedure system and event system, because I think some of the creators find the first one more comfortable other part the second system. Also I have problems with MCreator 1.7.4, I can't make shapeless recipes or recipes with enchantments and blocks with not regular block model. Can you tell me how to fix that, maybe I am doing something wrong?