How is the curve with equation $1/x^4 + 1/y^4 = 1$ called?

Question

Well what is the graph for

$$\frac 1{x^4} + \frac 1{y^4} = 1$$ called?

According to $ Wolfram-Alpha$:

http://www.wolframalpha.com/input/?i=plot+1%2Fx%5E4%2B1%2Fy%5E4%3D1+and+y%3Dx+and+y%3D-x

PLOT http://www4b.wolframalpha.com/Calculate/MSP/MSP8501gdi5621a7dbhg7c00004c68aci636bef167?MSPStoreType=image/gif&s=57&w=398.&h=300.&cdf=RangeControl

( $--$ Where the blue one is the plot for $1\over x^4 $+$1\over y^4$ = $1$ $--$ )

What is this type of graph called? (Eg: duo hyperbolas or something)

or even the graph to

$x^4 + y^4$ $=1$

( like the icons of iOS 7 :-) ) AS IN :

http://www.wolframalpha.com/input/?i=plot+x%5E4%2By%5E4%3D1

PLOT 2 http://www4b.wolframalpha.com/Calculate/MSP/MSP36911cha3ecd4675h7ci00004a14b488a8ab547c?MSPStoreType=image/gif&s=33&w=296.&h=300.&cdf=RangeControl

called

Answer 1

The terms superhyperbola and superellipse are in occasional use (and fit well with today's "supermoon" thing). From page 96 of this book:

Superconics are similar to conics except that trigonometric terms are raised to arbitrary power. A superellipse is $$x=a\cos^e \theta,\quad y=b\sin^e \theta$$ and a superhyperbola is $$x=a\sec^e \theta,\quad y=b\tan^e \theta$$

As Rahul pointed out, Wikipedia has the article Superellipse. But no article for superhyperbola. Maybe the name triggered someone's "you must be kidding" instinct? At least, the article Superquadrics mentions superhyperboloids, which are surface analogues of superhyperbola.