Well, here is an old standby:

$_=q(print qq(\$_=q($_);eval\n));eval
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And here is a clever one I originally saw ages ago on clpm (posted by mjd I think, but I could be wrong about that). Save the following line to a file named "/tmp/p" and run as: perl /tmp/p

Illegal division by zero at /tmp/p line 1.
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