This is another one I like in Gruul
Being instant allows you engineer further advantage with it than just a mana one
no treasure is safe from a goblin." Captain Lannery Storm P/T Number 645 Language English Legal Formats Commander, Legacy, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Modern, Pauper, Pioneer, Standard, Timeless Rulings (7/13/2018) An artifact is "tapped for mana" when a player activates a mana ability of an artifact that includes (the tap symbol)
But if you change this with something like Opalescence (or are using the Faceless One), then your background commander would be affected and could be targeted by anything that says commander creature. Most of the cards that refer to commander creatures instead of just commanders are background cards themselves
The most common pairing is Numa, Joraga Chieftain, but I prefer Thrasios, Triton Hero (one of Magic's best merfolks) or Tana, the Bloodsower for a better color identity