Translation pf Sherry's Soliloquy (file 979)
For anyone interested, I did a quick google search and found this, dunno how accurate it is, since I don't follow Naruto, but it sounds convincing.
Some basics first.
Consider the sentence: "I am Naruto"
The polite Japanese translation is: "Watashi wa Naruto desu".
The plain/conversational form is: "Watashi (wa) Naruto da".
Here the "wa" particle, which marks the subject of the sentence, Watashi here, can be dropped (but not always).
Moreover "desu" is shortened to "da".
Now, Naruto has a verbal tic (inherited from his mother) wherein he adds a "tebayo" which roughly translates to "you know". AFAIK there is no proper equivalent. People in general have such tic's; "like", "so" etc are some examples.
Also note that in Japanese, "yo" is a word which is used to indicate that the listener may not be knowing about something that the speaker is saying. I am not certain of the "teba" part. You might be interested to know that Naruto's mom Kushina also has a verbal tic. In her case she adds a "tebane" instead of a "tebayo". The "ne" gives a sense of "like this/that" (someone can correct this interpretation).
Wrapping it all up: "Watashi (wa) Naruto dattebayo" would effectively mean "I am Naruto, you know" or "I am Naruto, believe it".