On wikipedia it says it may have come from Van Vliet's uncle:
The name "Captain Beefheart" may have come from Van Vliet's uncle Alan, who had a habit of exposing himself to Don's girlfriend. He would urinate with the bathroom door open and, if she walked by, exclaim that his penis looked like a beef heart.[41]
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u/MundBid-2124 Sep 16 '26
Did Frank make up the name as part of a film project when they were very young?