The above is a Wikiwhale (Megaptera wikipediensis). It is used for the purpose of making major adjustments to clue levels in Wikipedians when a trout just doesn't cut it. Besides, who doesn't want to be squished? For experienced editors who have done something rather minor, use a Trout.
Place {{Whale}} on the talk page of the user you wish to communicate with. This will produce the above message.
Any of the following inline, comment-level templates can be converted into {{Resolved}}-style hatnotes by using {{Resbox}} to put a box around the icon and text.
{{enUici|Wikipedia:List of discussion templates|List of discussion templates]], a more linear table of essentially the same set of templates
Template:Resolved/See also, the smaller family of thread-level hatnote templates, similar to the above but with a box around them; any template above can be converted to one of those with {{Resbox}}