just-monsters: 油赤子 (あぶらあかご) or Abura-akago (Oil Baby)  Illustrated in Sekien Toriyama’s Konjaku...

just-monsters:

油赤子 (あぶらあかご) or Abura-akago (Oil Baby) 

Illustrated in Sekien Toriyama’s Konjaku Gazu Zoku Hyakki, this infant which licks the oil from an andon lamp is accompanied with the following explanation:
" 近江国　（あふみのくに）　大津の八町に
玉のごとくの火飛行　（ひぎやう）　する事あり。
土人云、むかし志賀の里に油をうるものあり、
夜毎に大津辻の地蔵の油をぬすみけるが、
その者死て魂魄炎となりて今に迷ひの火と
なれるとぞ。しからば油をなむる赤子は此もの
の再生せしにや。”

In the eighth town of Ōtsu in Ōmi (“Afumi”) Province there exists a flying ball-like fire.
The natives say that long ago in the village of Shiga there was a person who stole oil, and every night he stole the oil from the Jizō of the Ōtsu crossroads, but when this person died his soul became a flame and even now they grow accustomed to this errant fire.
If it is so then the baby which licks the oil is this person’s rebirth. ¹
Sekien seems to have based this image on a story from the ^{Shokoku Rijin Dan}, published in 1746, in which an oil merchant who steals oil from the Jizō statue at the Ōtsu crossroads is punished by being transformed posthumously into a ghostly flame.²

1. Toriyama p. 94.

2. Kaii Yōkai Denshō Database: Konpaku En

information from obakemono.com