Replace the Default Anonymous Avatar on Blogger Comments
Step 1. Go to Dashboard - Template - click on the Edit HTML button
...click anywhere inside the code area and open the template search box by pressing the CTRL + F keys
Step 2. Type or paste this code in the search box, then hit Enter to find it:
</body>Step 3. Just above the </body> tag, add the following code:
<script src='http://code.jquery.com/jquery-latest.js'/>Step 4. Save the changes by clicking on the Save Template button
<script>
$("img[src='http://img1.blogblog.com/img/anon36.png']")
.attr('src', 'https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcIrFW1RcLDBpbCEcEUJ_G30XTg4lL7hYs7SbR55XXtc6lpbU33xnHOAzvuIpz1LCeCcW_GBgY9nyQT6dQWS8HLo5ksN3VDPRD_KB94kyT7zmeNqFirBVcG-ll5K16AyW8mRhyeIzGxKE/s1600/default_avatar.gif')
.ssyby('blank')
</script>
<script src='http://code.jquery.com/jquery-latest.js'/>
<script>
$("img[src='http://img2.blogblog.com/img/b36-rounded.png']")
.attr('src', 'https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgshJzqjH6O1DC0YOsh9qJHh_wz3KnX_YWhjrVpsBNxYuCdX8lFnSGcveOmPoZAbsISPniRgLOxKx2i4DwRXh1A77KFri0xqICPLclgSnuH91HgIADHfzdoXnqGjLaH_lP0v5bfGgturHo/s1600/blogger-user.png')
.ssyby('blank')
</script>
Changing the default avatar
For Anonymous users: Replace the code in red with your image addressFor Blogger users: Replace the URL in blue with your own.
You can choose an avatar from here and then copy the url of it:
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcIrFW1RcLDBpbCEcEUJ_G30XTg4lL7hYs7SbR55XXtc6lpbU33xnHOAzvuIpz1LCeCcW_GBgY9nyQT6dQWS8HLo5ksN3VDPRD_KB94kyT7zmeNqFirBVcG-ll5K16AyW8mRhyeIzGxKE/s200/default_avatar.gif
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlLH3EQqTDSDweDXuQ-IsaI2AAyUDNUMkdSgNfEhBp89c56uSldQhhM8mpXQmhkCNub8ziI9G21N3frPUW6veiVihWFdd-b6rmTRhWAYBxyWZlcbgq0PcdWedrzi_Zd4CskqkgooFlt1A/s1600/facebook.gif
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_w76tbBNGtcVlZ3FfsPLbDexeq83jExbbbdTDHkkC_XNIawbsa7Kcj-47qf5o0RdOOQj7lqgLQp3OkwinQQOYy7c-RuaqcQy89h4AQUWOdjIi3YxV7PNQ0TYip6f7UNAHHszpyUoPEN8/s1600/anonymous3.png
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiKg__1Jyh9AwivonoCLVBwAOvXiycc7dbH6t8w1ceDuQ9jeusG35vEBpv5Jlq4qKr9RE7axocNZm2xMnr0BrjMWE-LbVbY6WcKYfl8RZn0398wLFAOx8WAiZTqqYQnaNe4dvrxBAWGg17/s1600/blogger-user.png
That's it! If you found this trick useful, please consider sharing it.