Ok here are my entries. Since you asked for silly onces, these were so stupid they made myself laugh out loud.
Fair warning, I am no photoshop specialist. But I am a master with paint:
The Anthills Have Eyes 
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Apocalypse Cow 
(first I was going to go with Catopalypse Now, but this one seems funnier.)
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American History B 
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The Codfather 
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Elephantasm
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Llamadeus
More silly ones:
From tusk til paw
WALL-RUS
Yacksi Driver
Koal About Eve
An Officer Panda Gentleman
edit:
that lamadeus quote:
the madness
the murder