Conversation so far:
What did Spike Milligan write during the second world war?
During the Second World War, Milligan served as a signaller in the 56th Heavy Regiment Royal Artillery, D Battery (later 19 Battery), as Gunner Milligan, 954024.
How long was he there?
CANNOTANSWER.
did he write while there?
After his call-up, but before being sent abroad, he and fellow musician Harry Edgington (1919-1993) (whose nickname 'Edge-ying-Tong', inspired one of Milligan's most memorable musical creations, the "Ying Tong Song".
What was it about?
filled with puns and skewed logic, as a way of staving off the boredom of life in barracks.
Did he put out anything else during the war?
CANNOTANSWER.

Question: What else did he do?
Self-contained rewrite: Aside from Gunner what else did Milligan do?