Do you have Nicknames for your servants?

When I don't use portmanteau names like Jalter, I usually go with a name that fits the them similar to classes with the '-er' suffix. Ex: Blitzer for Brave Liz and (Slave) Driver for Medb.

Cu Chulainn: The Dog
Artoria Lancer: Boobtoria
Saber Gilles: Second greatest cool ever
Leonidas: SPARTA

Among other things.

I call Ushiwara Tanuki girl because of the tail.
Liz I actually call Rory because she reminds me of Rory Mercury from Gate. They're both gothlolis with oversized weapons.
Okita is Sakura Saber.

Mash = Mash-potatoes
Cu Chulainn = Choo
I mostly just shorten the names (Ibaraki-Douji is Ibaraki, Hassan of the Serenity is Serenity etc.). Random pet-peeve - I've seen Tamamo written as Tanamo here too many times.

Cu = aniki
Mash= mashu-mallow
Lancer artoria = puff puff
Archer artoria = buttoria
Ushiwakamaru = hasoutobi
Waver = salaryman
Fergus = uncle kaz
Bedivere = hash-slinging slapper