Invertir un gif?
No sé si te refieres a esto ...
<img src="imagen.gif">
<BR><BR>
<img id="reflect" src="imagen.gif" width=70 heigth=70>
<br>
<script language="JavaScript1.2">
function f1(){
setInterval("mdiv.filters.wave.phase+=10",100);
}
if (document.all){
document.write('<img id=mdiv src="'+document.all.reflect.src+'" style="filter:wave(strength=3,freq=3,phase=0,lightstrength=30) blur() flipv()" width=50 heigth=50>')
window.onload=f1
}
</script>
<img src="imagen.gif">
<BR><BR>
<img id="reflect" src="imagen.gif" width=70 heigth=70>
<br>
<script language="JavaScript1.2">
function f1(){
setInterval("mdiv.filters.wave.phase+=10",100);
}
if (document.all){
document.write('<img id=mdiv src="'+document.all.reflect.src+'" style="filter:wave(strength=3,freq=3,phase=0,lightstrength=30) blur() flipv()" width=50 heigth=50>')
window.onload=f1
}
</script>