Davis. The letter D.
With an amount like $1,000,000,000 there are endless possibilities.
Logical Davis:
The letter D feels generous. The letter D is for Donate.
Internet Davis:
Everyone knows D is for Dank memes.
Greed Davis:
D is for Diamonds.
Cute Davis:
D is for Dogs.
Bob the Builder:
D is for Duct tape.