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/AVvXsEgaVYAJCod6YkK-Kwy80G_ppVnyCJSbeLAebgaHr6XPSfaSOSC81yPhgHIPv7hzcR0bDG1vmj0DdpLmkn-5Ek9FZJC_4lsmodgawXeSeoGqgrX_eRWMN2eQ_RrgR6_0O5d8DuhOYhpYwcc/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/AVvXsEj-qWdy0E9eZ35-nmj220yoPwI8GEWhTRTkBl3YG8I5n1JmLzhtNCyBj-Uyh9Cg3jeNQhlcFhTYG0h5SXH2-zaGB_tGqdVwZNGbMVYopltKZ1v14LzUSmBCL3Yqx4QuNpaD9lE9AqjwyCw/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/AVvXsEgaVYAJCod6YkK-Kwy80G_ppVnyCJSbeLAebgaHr6XPSfaSOSC81yPhgHIPv7hzcR0bDG1vmj0DdpLmkn-5Ek9FZJC_4lsmodgawXeSeoGqgrX_eRWMN2eQ_RrgR6_0O5d8DuhOYhpYwcc/s200/default_avatar.gif
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmMXJiPfQN1IHZ80NPgR_AAuKrEzP9CVDsPjBC6moHgqf0DjnTidHYXWTh7WeJAFTwLAg0MhRYYFM1_s8BTA_rr2C1GLSDW1Hh98xpkmRE7OhfYzJ367aLjK95Qb6YAfPC1ZunOv8Yo7o/s1600/facebook.gif
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju3NcHsXLZ6dLJ8WRKc5O0hVtionsaDsNL2ZUezR4wVCGF-JBbihWs_4iDVqYu4GabXGw1jRTRX7r4T4H8-TzTo-AiSv-MGwJL71ot1Zrr1bDLSKKuyuCJQ5fJyWes2iDh8RpOrIhyphenhyphen7Do/s1600/anonymous3.png
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUQmapVQ1ZP_EfFweZGkBzN5TW7wwDmXjoxFS6gTkb2I4SSEMs3WnVeo-QyySCkOfN9zaaHSTBUFLY24SKoQLWuOwLEZhlsH2ysA0h4Lei-B7tdn3CX0wKdUfOA85Twzx-rVfHt9uSKyzU/s1600/blogger-user.png
That's it! If you found this trick useful, please consider sharing it.