Brain
Brain
My Brain [Picture of Brain. Line points at a highlighted area.] Section that is devoted, no matter where I go in life, to planning the ultimate tree house*. *Oh man, it would be like Swiss Family Robinson, but with multiple trees connected by... hey come up to my room and see the blueprints!

The Swiss Family Robinson is a novel by the Swiss pastor and writer Johann David Wyss . In the novel, a shipwrecked family builds a tree house as good as a normal house complete with library and mechanical contraptions.
Growing up, many children grow a fascination with tree houses. Tree houses are a child's own special place to do stuff away from their parents, have some autonomy, perhaps form a club. The obsession with tree houses usually fades once a child reaches their teenage years, but of course some of us never grow up. Being an adult geek/scientist who still enjoys childish things, Randall wants to build a sophisticated tree house rather than a simple one, taking the theme from the above-mentioned novel.
The title text makes reference to the regular xkcd joke about how terrifying Velociraptors from the movie Jurassic Park are. But they never can reach a tree house, just because it's too high, as you can see here 87: Velociraptors .
"Raptors" might refer to the informal bird group, hawks and owls and such, a joke relying on the previous infatuation with velociraptors.
My Brain [Picture of Brain. Line points at a highlighted area.] Section that is devoted, no matter where I go in life, to planning the ultimate tree house*. *Oh man, it would be like Swiss Family Robinson, but with multiple trees connected by... hey come up to my room and see the blueprints!
