Bats with Umbrella and Fan, Tsukioka Yoshitoshi, c.1880s.
Bats look sinister to Western eyes, but in Japan they've always meant the opposite. The word for bat, komori, shares a character that can also be read fuku, meaning good fortune, the exact character in the lucky god Fukurokuju's name. So these two bats squabbling over an umbrella and fan aren't omens. They're a joke about luck getting into a scuffle over borrowed props.