documentclass{memoir}

usepackage{pgfcore}
usepackage{pgfplots}
usetikzlibrary{arrows, arrows.meta}

begin{document}
resizebox{linewidth}{!}{
  begin{tikzpicture}[>=stealth']
  foreach arrowa [count=i from 1] in {stealth, Stealth, {Stealth[round]}, >} {
    path (0.0, {-0.3 * i}) edge [-arrowa] (1.0, {-0.3 * i});
  }
end{tikzpicture}
}
end{document}

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%
    advancepgfutil@tempdima by.3pgflinewidth%
    pgfutil@tempdimb=6pgfutil@tempdimaadvancepgfutil@tempdimb by.5pgflinewidth%
    pgfarrowsleftextend{+-pgfutil@tempdimb}
    pgfutil@tempdimb=2pgfutil@tempdimaadvancepgfutil@tempdimb by0.5pgflinewidth%
    pgfarrowsrightextend{+pgfutil@tempdimb}
  },
  drawing code = {
    pgfutil@tempdima=0.28pt%
    ifdimpgfarrowlinewidth=pgflinewidthelsepgfsetlinewidth{pgfarrowlinewidth}fi
    advancepgfutil@tempdima by.3pgflinewidth%
    pgfsetdash{}{+0pt}
    ifpgfarrowroundjoinpgfsetroundjoinelsepgfsetmiterjoinfi
    pgfpathmoveto{pgfqpoint{2pgfutil@tempdima}{0pgfutil@tempdima}}
    pgfpathcurveto
    {pgfqpoint{-.5pgfutil@tempdima}{.5pgfutil@tempdima}}
    {pgfqpoint{-3pgfutil@tempdima}{1.5pgfutil@tempdima}}
    {pgfqpoint{-6pgfutil@tempdima}{3.25pgfutil@tempdima}}
    pgfpathcurveto
    {pgfqpoint{-3pgfutil@tempdima}{1pgfutil@tempdima}}
    {pgfqpoint{-3pgfutil@tempdima}{-1pgfutil@tempdima}}
    {pgfqpoint{-6pgfutil@tempdima}{-3.25pgfutil@tempdima}}
    pgfpathcurveto
    {pgfqpoint{-3pgfutil@tempdima}{-1.5pgfutil@tempdima}}
    {pgfqpoint{-.5pgfutil@tempdima}{-.5pgfutil@tempdima}}
    {pgfqpoint{2pgfutil@tempdima}{0pgfutil@tempdima}}
    pgfpathclose
    ifpgfarrowopenpgfusepathqstrokeelseifdimpgfarrowlinewidth>0ptpgfusepathqfillstrokeelsepgfusepathqfillfifi
  },
  parameters = {
    thepgfarrowlinewidth,%
    ifpgfarrowopen ofi%
    ifpgfarrowroundjoin jfi
  },
}