Ungulates. Because who doesn't like a hoofed animal?

My client machines are even-toed ungulates (order Artiodactyla) and my servers/IoT machines are odd-toed (order Perissodactyla). I'm typing this on Gazelle. My router is called Quagga, both after the extinct zebra subspecies and the routing protocol software (I don't use it any more but hey, it's a router).

Biological taxonomy is a great source of a huge number of systematic (and colloquial) names.

Every machine is named after what it does (although I do 1337-ify the names, because I'm still a late 90s IRC teen at heart). If you've ever been onboarded into a sysadmin role where all the machines are named with whatever whimsical naming scheme each department chose, you'll fast develop a visceral hatred for non-descriptive naming schemes. The fifth time you get a ticket saying something like 'Hedwig is down' and you have to go crawling through three layers of linked files on SharePoint to find what and where 'Hedwig' is, you'll be ready to beat the person who named it to death, and that attitude tends to persist to your home naming scheme :p

I'm incredibly boring. I name them with the company/model name. And what role they have appended.

Discworld characters. My storage servers name is Luggage, my phone is 'Ig', the vacuum is named after a monk.

Depending on the size of the machine I'll call it big/large/huge/small/Lil then a human name like John. BigJohn is my main server and hopefully one day he can get an upgrade and become large John.