Out of memory when spawning a ghast in farlands

Heres the Crash Report:

Minecraft has crashed!      
      ----------------------      

Minecraft has stopped running because it encountered a problem; Ticking entity

A full error report has been saved to C:\Users\Owner\AppData\Roaming\.minecraft\crash-reports\crash-2012-12-14_12.26.30-server.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash :(



--- BEGIN ERROR REPORT 54097ca4 --------
Full report at:
C:\Users\Owner\AppData\Roaming\.minecraft\crash-reports\crash-2012-12-14_12.26.30-server.txt
Please show that file to Mojang, NOT just this screen!

Generated 12/14/12 12:26 PM

-- Head --
Stacktrace:
	at java.util.Arrays.copyOf(Arrays.java:2245)
	at java.util.Arrays.copyOf(Arrays.java:2219)
	at java.util.ArrayList.grow(ArrayList.java:213)
	at java.util.ArrayList.ensureCapacityInternal(ArrayList.java:187)
	at java.util.ArrayList.add(ArrayList.java:411)
	at any.a(SourceFile:24)
	at amj.e(SourceFile:557)
	at amj.a(SourceFile:552)
	at xv.a(SourceFile:910)
	at qg.a(SourceFile:157)
	at qg.bn(SourceFile:90)
	at md.c(SourceFile:1102)
	at md.j_(SourceFile:526)
	at qg.j_(SourceFile:62)
	at xv.a(SourceFile:1317)
	at in.a(SourceFile:451)
	at xv.g(SourceFile:1296)

-- Entity being ticked --
Details:
	Entity Type: Ghast (qg)
	Entity ID: 1371824
	Name: Ghast
	Exact location: 29999288.00, 84.00, 29999892.00
	Block location: World: (29999288,84,29999892), Chunk: (at 8,5,4 in 1874955,1874993; contains blocks 29999280,0,29999888 to 29999295,255,29999903), Region: (58592,58593; contains chunks 1874944,1874976 to 1874975,1875007, blocks 29999104,0,29999616 to 29999615,255,30000127)
	Momentum: 0.00, 0.00, 0.00
Stacktrace:
	at xv.h(SourceFile:1195)
	at in.h(SourceFile:363)

-- Affected level --
Details:
	Level name: Random Creative Mode World
	All players: 1 total; [iq['MC_2the2'/246, l='Random Creative Mode World', x=29999190.94, y=-5.04, z=30000000.49]]
	Chunk stats: ServerChunkCache: 441 Drop: 0
	Level seed: 4517515599353190928
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 0 game time, 0 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at net.minecraft.server.MinecraftServer.r(SourceFile:751)
	at net.minecraft.server.MinecraftServer.q(SourceFile:686)
	at bdo.q(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:620)
	at fy.run(SourceFile:856)

-- System Details --
Details:
	Minecraft Version: 1.4.5
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_09, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 46012104 bytes (43 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 13845150 (775328400 bytes; 739 MB) allocated, 13845150 (775328400 bytes; 739 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [iq['MC_2the2'/246, l='Random Creative Mode World', x=29999190.94, y=-5.04, z=30000000.49]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

java.lang.OutOfMemoryError: Java heap space
	at java.util.Arrays.copyOf(Arrays.java:2245)
	at java.util.Arrays.copyOf(Arrays.java:2219)
	at java.util.ArrayList.grow(ArrayList.java:213)
	at java.util.ArrayList.ensureCapacityInternal(ArrayList.java:187)
	at java.util.ArrayList.add(ArrayList.java:411)
	at any.a(SourceFile:24)
	at amj.e(SourceFile:557)
	at amj.a(SourceFile:552)
	at xv.a(SourceFile:910)
	at qg.a(SourceFile:157)
	at qg.bn(SourceFile:90)
	at md.c(SourceFile:1102)
	at md.j_(SourceFile:526)
	at qg.j_(SourceFile:62)
	at xv.a(SourceFile:1317)
	at in.a(SourceFile:451)
	at xv.g(SourceFile:1296)
	at xv.h(SourceFile:1195)
	at in.h(SourceFile:363)
	at net.minecraft.server.MinecraftServer.r(SourceFile:751)
	at net.minecraft.server.MinecraftServer.q(SourceFile:686)
	at bdo.q(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:620)
	at fy.run(SourceFile:856)
--- END ERROR REPORT 4f6dec69 ----------