It's possible to change the default icon (version >= 2.10d).

{mosmap icon='<Url icon>'|iconwidth='60'|iconheight='52'|iconanchorx='58'|
iconanchory='52'|iconinfoanchorx='34'|iconinfoanchory='1'|iconshadow='<Url shadow'|
iconshadowwidth='60'|iconshadowheight='52'|iconshadowanchorx='34'|
iconshadowanchory='0'|icontransparent='<Url Trans>'|iconimagemap='<image map>'|tooltip='Tooltip'
|text='Custom Icon'}

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Even an animated icon should work:

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