A demonstration of some awful things you can do if you give your Lambda's role full access to the Lambda API.
All of these require the LambdaFullAccess managed policy.
This Lambda updates one of its own environment variables.
This Lambda replaces its own code.
This Lambda deletes itself from AWS.
This Lambda creates a copy of itself in the same acct/region.
This Lambda creates two copies of itself in the same acct/region, then invokes them.
It panics and exits if the account/region already contains more than 100 Lambda functions, because I'm not completely evil.