Skeleton riding a turtle or parrot crashes the game

WHEN REPLICATING THIS GLITCH PLEASE MAKE A NEW WORLD AS IT HAS MADE MY CURRENT WORLD UN-USABLE I did back up my world but most of my recent updates to it are on 18w50a and I haven't backed it up since :c

Crash report

18w50a\: [^crash-2018-12-23_00.43.35-server.txt]

Description: Ticking entity

java.lang.ClassCastException: ale cannot be cast to alf
	at akg.c(SourceFile:21)
	at ajc.a(SourceFile:102)
	at ahf.cQ(SourceFile:609)
	at ahe.k(SourceFile:2035)
	at ahf.k(SourceFile:474)
	at apu.k(SourceFile:33)
	at apc.k(SourceFile:137)
	at ahe.W_(SourceFile:1886)
	at ahf.W_(SourceFile:285)
	at apu.W_(SourceFile:45)
	at agv.aJ(SourceFile:1688)
	at ahe.aJ(SourceFile:2176)
	at apc.aJ(SourceFile:142)
	at bbp.a(SourceFile:1164)
	at uq.a(SourceFile:391)
	at bbp.g(SourceFile:1147)
	at bbp.a(SourceFile:1212)
	at uq.a(SourceFile:391)
	at bbp.g(SourceFile:1147)
	at bbp.m_(SourceFile:1029)
	at uq.m_(SourceFile:307)
	at net.minecraft.server.MinecraftServer.b(SourceFile:844)
	at net.minecraft.server.MinecraftServer.a(SourceFile:773)
	at dqk.a(SourceFile:125)
	at net.minecraft.server.MinecraftServer.run(SourceFile:639)
	at java.lang.Thread.run(Thread.java:745)

How to reproduce

Use the following command

/summon turtle ~ ~ ~ {Passengers:[{id:"minecraft:skeleton"}]}

After a brief moment the game will crash and every time you attempt to join the world the game will crash over and over.