1) Dennis the Dachshund. Definitely German, and the definite "brains behind the operation." Think about it - without Dennis to manipulate him, Larry would be a sweet little lamb who never got into any trouble at all. Dennis is the corrupter who always gets Larry into trouble. This may perhaps have connotations with Satan as the ultimate corrupter. The German accent would subconsciously suggest that all Germans are an evil, corrupting influence and not to be trusted.
2) All of Larry's adventures suggest that the police are the enemy. Larry and Dennis seem to go out of their way to make hoax call-outs to Ernest the police-man, try and make him look stupid and have even lowered themselves to blackmailing him, or at least, to threatening him with the possibility of having all of Toytown laughing at him and disrespecting him when he threatens to reveal what they have been up to as it will also make Ernest look incredibly stupid and bad at his job.
3) Looking for Faeries in a mushroom field. Need I say any more on that one?