Check the state of this sump plug

[Reardiff]

Went to change oil on the 2011 forester and found this monstrosity. 
Other than pumping the oil out does anyone have any suggestions to get this out. It clearly used to be a 14mm. I’m wondering if that’s the original paint on it? 
cheers Fraser 

[Mr B]

What I do in these scenarios is first try knock on a 13mm, if that no go try some grip/rounded fastener sockets & if that still no go mig weld a nut to the plug head and semi gently air impact it out .

If you got decent quality vise grip pliers you might do it with them but it likely chew it up real bad leaving it only suitable for welding nut on .