The Edgehog was invented in 1966 by John Driver. The name was come up
with first, and then the piece was invented to fit. Actually, John
Driver invented two types of Edgehog, one more limited than the other; I
will refer to them as regular and limited Edgehogs.

A chess variant featuring the Edgehog has also been invented: Edgehog Chess.

Movement: Regular Edgehog

The regular Edgehog is a limited Queen. It moves an arbitrary number
of squares in a horizontal, vertical, or diagonal direction, but may
not jump over occupied squares, and must either begin or end on an
edge square.

Regular Edgehogs take in the same way as they move without taking.

Movement diagram: Regular Edgehog

Note that a regular Edgehog on an edge square may move just like a Queen.

Movement: Limited Edgehog

The limited Edgehog is also a limited Queen. It moves an arbitrary
number of squares in a horizontal, vertical, or diagonal direction,
but may not jump over occupied squares, and if it begins the move on
an edge square, must end the move on a non-edge square, and if it
begins the move on a non-edge square, must end the move on an edge
square.

Limited Edgehogs take in the same way as they move without taking.

Movement diagram: Limited Edgehog

A limited Edgehog on a non-edge square would move just like a regular
Edgehog in the previous diagram.