diff --git a/graphene/types/mutation.py b/graphene/types/mutation.py
index f87fd570..5266ef1c 100644
--- a/graphene/types/mutation.py
+++ b/graphene/types/mutation.py
@@ -5,6 +5,7 @@ from .objecttype import ObjectTypeMeta, ObjectType
 from .field import Field
 
 from ..utils.props import props
+from ..utils.is_base_type import is_base_type
 
 
 class MutationMeta(ObjectTypeMeta):
@@ -16,15 +17,22 @@ class MutationMeta(ObjectTypeMeta):
         assert resolver, 'All mutations must define a mutate method in it'
         return partial(Field, cls, args=field_args, resolver=resolver)
 
-    def construct(cls, bases, attrs):
-        super(MutationMeta, cls).construct(bases, attrs)
-        if not cls._meta.abstract and cls._construct_field:
-            Input = attrs.pop('Input', None)
+    def __new__(cls, name, bases, attrs):
+        super_new = super(MutationMeta, cls).__new__
+
+        # Also ensure initialization is only performed for subclasses of Model
+        # (excluding Model class itself).
+        if not is_base_type(bases, MutationMeta):
+            return type.__new__(cls, name, bases, attrs)
+
+        Input = attrs.pop('Input', None)
+
+        cls = super_new(cls, name, bases, attrs)
+        if cls._construct_field:
             field_args = props(Input) if Input else {}
             cls.Field = cls.construct_field(field_args)
         return cls
 
 
 class Mutation(six.with_metaclass(MutationMeta, ObjectType)):
-    class Meta:
-        abstract = True
+    pass
diff --git a/graphene/types/objecttype.py b/graphene/types/objecttype.py
index 3ea63d52..37061822 100644
--- a/graphene/types/objecttype.py
+++ b/graphene/types/objecttype.py
@@ -124,6 +124,9 @@ class ObjectType(six.with_metaclass(ObjectTypeMeta)):
         # GraphQL ObjectType acting as container
         args_len = len(args)
         fields = self._meta.graphql_type.get_fields().values()
+        for f in fields:
+            setattr(self, getattr(f, 'attname', f.name), None)
+
         if args_len > len(fields):
             # Daft, but matches old exception sans the err msg.
             raise IndexError("Number of args exceeds number of fields")
diff --git a/graphene/types/tests/test_schema.py b/graphene/types/tests/test_schema.py
index c3fd8ead..b42a9343 100644
--- a/graphene/types/tests/test_schema.py
+++ b/graphene/types/tests/test_schema.py
@@ -1,6 +1,6 @@
 from ..scalars import String
 from ..field import Field
-from ..objecttype import ObjectType, implements
+from ..objecttype import ObjectType
 from ..interface import Interface
 from ..structures import List
 from ..schema import Schema
diff --git a/graphene/utils/copy_fields.py b/graphene/utils/copy_fields.py
index 59239a12..19c5ef38 100644
--- a/graphene/utils/copy_fields.py
+++ b/graphene/utils/copy_fields.py
@@ -5,7 +5,7 @@ from ..types.field import Field, InputField
 def copy_fields(like, fields, **extra):
     _fields = []
     for attname, field in fields.items():
-        field = like.copy_and_extend(field, attname=attname, **extra)
+        field = like.copy_and_extend(field, attname=getattr(field, 'attname', None) or attname, **extra)
         _fields.append(field)
 
     return OrderedDict((f.name, f) for f in _fields)
diff --git a/graphene/utils/is_graphene_type.py b/graphene/utils/is_graphene_type.py
index 963db8a8..d252fa44 100644
--- a/graphene/utils/is_graphene_type.py
+++ b/graphene/utils/is_graphene_type.py
@@ -3,17 +3,19 @@ import inspect
 
 def is_graphene_type(_type):
     from ..types.objecttype import ObjectType
+    from ..types.mutation import Mutation
     from ..types.inputobjecttype import InputObjectType
     from ..types.interface import Interface
     from ..types.scalars import Scalar
     from ..types.enum import Enum
 
-    if _type in [Interface, InputObjectType, ObjectType]:
+    if _type in [Interface, InputObjectType, ObjectType, Mutation]:
         return False
     return inspect.isclass(_type) and issubclass(_type, (
         Interface,
         ObjectType,
         InputObjectType,
         Scalar,
+        Mutation,
         Enum
     ))