chest stand
Japanese name: キングアラジンの真似 ('King Aladdin no Mane', 'King Aladdin Impression')
Other name: エピオン (Epyon)
The pose where you place your chest on the ground, and curve your back upwards and over until both of your legs are stretching out in front of you. In contortionist terms, it’s called a 'chest stand'. (This is sometimes used to refer to the 'triple fold' as well.)
King Aladdin is the villain and thief who was formerly a magician in 'Kabe Nuke Otoko (The Man Who Passes through Walls)', which is the first episode of the horror TV drama, '怪奇大作戦 (Kaiki Daisakusen)' (English title: 'Operation: Mystery!'). In the drama, he rolls away in the chest stand position, and laughing, disappears into the wall as though being plastered into it.
The TV series in itself isn't that well known. However, Hyoudou Makoto, one of the characters in Yuuki Masami's 'Kyuukyoku Choujin R', does this pose as his speciality and so the name became popularised as a result.
More recently, this pose has also been called the 'Gundam Epyon Mobile Armour Mode'. The Gundam Epyon in the Gundam Wing is able to transform into what looks like a two-headed dragon. This design is meant to be breathtaking when seen from above but from below, you can really understand how it just looks as though it's doing a simple 'chest stand'.