Thanks to @Symbol1, copied this code from pgflibraryarrows and started adapting it to arrows.meta. length, width, and inset don't work. It should be called as Stealthy[round].
\pgfdeclarearrow{
name=Stealthy,
defaults={
length = +3.6pt +5.4,
width' = +0pt +0.5,
inset' = +0pt 0.5,
line width = +0pt 1 1,
},
setup code = {
\pgfutil@tempdima=0.28pt%
\advance\pgfutil@tempdima by.3\pgflinewidth%
\pgfutil@tempdimb=6\pgfutil@tempdima\advance\pgfutil@tempdimb by.5\pgflinewidth%
\pgfarrowsleftextend{+-\pgfutil@tempdimb}
\pgfutil@tempdimb=2\pgfutil@tempdima\advance\pgfutil@tempdimb by0.5\pgflinewidth%
\pgfarrowsrightextend{+\pgfutil@tempdimb}
},
drawing code = {
\pgfutil@tempdima=0.28pt%
\ifdim\pgfarrowlinewidth=\pgflinewidth\else\pgfsetlinewidth{\pgfarrowlinewidth}\fi
\advance\pgfutil@tempdima by.3\pgflinewidth%
\pgfsetdash{}{+0pt}
\ifpgfarrowroundjoin\pgfsetroundjoin\else\pgfsetmiterjoin\fi
\pgfpathmoveto{\pgfqpoint{2\pgfutil@tempdima}{0\pgfutil@tempdima}}
\pgfpathcurveto
{\pgfqpoint{-.5\pgfutil@tempdima}{.5\pgfutil@tempdima}}
{\pgfqpoint{-3\pgfutil@tempdima}{1.5\pgfutil@tempdima}}
{\pgfqpoint{-6\pgfutil@tempdima}{3.25\pgfutil@tempdima}}
\pgfpathcurveto
{\pgfqpoint{-3\pgfutil@tempdima}{1\pgfutil@tempdima}}
{\pgfqpoint{-3\pgfutil@tempdima}{-1\pgfutil@tempdima}}
{\pgfqpoint{-6\pgfutil@tempdima}{-3.25\pgfutil@tempdima}}
\pgfpathcurveto
{\pgfqpoint{-3\pgfutil@tempdima}{-1.5\pgfutil@tempdima}}
{\pgfqpoint{-.5\pgfutil@tempdima}{-.5\pgfutil@tempdima}}
{\pgfqpoint{2\pgfutil@tempdima}{0\pgfutil@tempdima}}
\pgfpathclose
\ifpgfarrowopen\pgfusepathqstroke\else\ifdim\pgfarrowlinewidth>0pt\pgfusepathqfillstroke\else\pgfusepathqfill\fi\fi
},
parameters = {
\the\pgfarrowlinewidth,%
\ifpgfarrowopen o\fi%
\ifpgfarrowroundjoin j\fi
},
}
roundis not round enough for you? – Qrrbrbirlbel Dec 17 '13 at 14:15stealth'sure looks good though, don't you think? – Neil G Dec 17 '13 at 14:21\pgfarrowsdeclare{stealth'}{stealth'}...frompgflibraryarrows.code.tex? There are nothing but Bézier curves. – Symbol 1 Mar 02 '15 at 10:08