Marmaduke has a really stupid addiction.

Marmaduke is chasing a squirrel while being walked by his owner-man, who is at the mercy of both an enormous, inconsiderate great dane and either an absurdly short leash or very poorly rendered perspective. Owner Man makes an asinine request that is unlikely to be granted.

Marmaduke and his owner-children decide to give con-artistry a try and attempt to scam several neighborhood ragamuffins out of some quarters, but Marmaduke's celebrity is called into question.

Marmaduke is disobeying his owner-lady's rule about having garden hoses in the house (they are not allowed). He is getting water all over the living room, which is probably one of the main reasons why Owner-Lady came up with the rule in the first place.

I haven't the foggiest.

Marmaduke has essentially ruined his owner-man's life, invading/ruining his dreams and turning his waking life into his "other nightmare."