Why the title: Unicorns, Almost?

This phrase is in reference to a line from Douglas' 1943 poem Aristocrats: “I think I am becoming a God”:

The noble horse with courage in his eye 
clean in the bone, looks up at a shellburst: 
away fly the images of the shires 
but he puts the pipe back in his mouth.

Peter was unfortunately killed by an 88; 
it took his leg away, he died in the ambulance. 
I saw him crawling on the sand, he said 
It’s most unfair, they’ve shot my foot off. 

How can I live among this gentle 
obsolescent breed of heroes, and not weep? 
Unicorns, almost, 
for they are falling into two legends 
in which their stupidity and chivalry 
are celebrated. Each, fool and hero, will be an immortal.

The plains were their cricket pitch 
and in the mountains the tremendous drop fences 
brought down some of the runners. Here then 
under the stones and earth they dispose themselves, 
I think with their famous unconcern. 
It is not gunfire I hear, but a hunting horn.

Keith Douglas, Tunisia, 1943.