cereal and choccy milk!?

Source Text

Interview with Nightow Yasuhiro about Vash and Wolfwood's profiles (source unknown)

Links

Tumblr source (Page photos + rest of translation by @uynumeotp)

Note

This is less of a translation and more of an explanation. There was confusion in the original post concerning Nicholas D. Wolfwood's joke middle name.
My original linked Tumblr post also contains a comment about length units (related to the previous reblog comment), but it was not concrete information at the time and I have more information in a separate post/page so that is ignored here for the time being.

Nicholas D. Wolfwood's middle name

Context

Original line:

◀名前の由来▶「駄ジャレで付けました。トータス松本さんがモデルなんでウルフルズから。ミドルネームのＤは「ドコノクミノモンジャワレスマキニシテシズメタロカコラ」の略です（笑）」

English translation (by @uynumeotp, spacing/romaji edited by me):

Name’s origin: It’s a pun. Tortoise Matsumoto is the model, so the name came from Ulfuls. The D in his middle name stands for “ドコノクミノモンジャワレスマキニシテシズメタロカコラ” (Dokono kumino monja ware sumaki ni shite shizumetaroka kora) (laughs)

Explanation

Converted to a readable state, this name is「どこの組のモンじゃワレ 簀巻きにして沈めたろかコラ」(something like "Which gang are ya in, punk!? I'mma roll ya up in a bamboo blind n' throw ya into the river!") which is a classic, stereotypical yakuza threat.

Wolfwood does give a sort of yakuza-like impression at first glance, with his suit, shades, and menacing vibe, so Nightow probably leant into that for the joke.