[RodgerTheGreat]

The turtle/tortoise note is correct for UK English, but in the US (where Id software was headquartered during the development of Quake), tortoises are considered a subset of "turtles". Per Webster:

> Turtle (noun): any of an order (Testudines synonym Chelonia) of terrestrial, freshwater, and marine reptiles that have a toothless horny beak and a shell of bony dermal plates usually covered with horny shields enclosing the trunk and into which the head, limbs, and tail usually may be withdrawn.

[leoc]

The naming of the ‘showturtle’ command may be a Logo reference https://people.eecs.berkeley.edu/~bh/docs/html/usermanual_6.... . It’s highly likely that Carmack encountered Apple Logo on the Apple II at some point. Someone should ask him …

[theandrewbailey]

> Trivia: The icon doesn't actually depict a turtle but a tortoise. A turtle swims in the water while a tortoise walks on land.

Turtles walk on land, too. All turtles are tortises? /s