Gravity Forms Spinner

The gravity forms spinner for ajax submit has a class associated with it: ‘gform_ajax_spinner’ for use in styling. This information is surprisingly hard to find on the googles. If you want to change the spinner image entirely, throw this filter in your functions:

add_filter( 'gform_ajax_spinner_url', 'aceify_custom_gforms_spinner' );
function aceify_custom_gforms_spinner( $src ) {
     return get_stylesheet_directory_uri() . '/img/loading.gif'; 
}

(obviously change the return value to whatever your spinner image location is)