diff --git a/redbot/core/core_commands.py b/redbot/core/core_commands.py
index 8e8661ebe..b8d55edde 100644
--- a/redbot/core/core_commands.py
+++ b/redbot/core/core_commands.py
@@ -1095,11 +1095,21 @@ class Core(commands.Cog, CoreLogic):
 
     @_set.command()
     @checks.is_owner()
-    async def avatar(self, ctx: commands.Context, url: str):
-        """Sets [botname]'s avatar"""
-        async with aiohttp.ClientSession() as session:
-            async with session.get(url) as r:
-                data = await r.read()
+    async def avatar(self, ctx: commands.Context, url: str = None):
+        """Sets [botname]'s avatar
+
+        Supports either an attachment or an image URL."""
+        if len(ctx.message.attachments) > 0:  # Attachments take priority
+            data = await ctx.message.attachments[0].read()
+        elif url is not None:
+            if url.startswith("<") and url.endswith(">"):
+                url = url[1:-1]
+
+            async with aiohttp.ClientSession() as session:
+                async with session.get(url) as r:
+                    data = await r.read()
+        else:
+            return await ctx.send(_("Please upload an attachment or provide an URL link."))
 
         try:
             await ctx.bot.user.edit(avatar=data)
@@ -1107,8 +1117,8 @@ class Core(commands.Cog, CoreLogic):
             await ctx.send(
                 _(
                     "Failed. Remember that you can edit my avatar "
-                    "up to two times a hour. The URL must be a "
-                    "direct link to a JPG / PNG."
+                    "up to two times a hour. The URL or attachment "
+                    "must be a valid image in either JPG or PNG format."
                 )
             )
         except discord.InvalidArgument: