I wanted this too, so I made a TamperMonkey userscript for it until it's an official feature:
// ==UserScript==
// @name Kagi Random Companion
// @namespace http://tampermonkey.net/
// @version 2025-11-29
// @description Get a new companion each time you visit Kagi!
// @match https://kagi.com/
// @icon https://kagi.com/apple-touch-icon.png
// @grant none
// ==/UserScript==
(async function() {
'use strict';
const companions = [
// 'default',
'doggo',
'kagibara',
'katto',
'kagiroo',
'doggo_orion',
'doggo_detective',
'doggo_sniff',
'doggo_fly',
'doggo_happy',
'doggo_spin',
'doggo_world',
'doggo_work',
// 'doggo_halloween',
]
const companion = companions[Math.floor(Math.random() * companions.length)]
await fetch("https://kagi.com/settings", {
method: "POST",
headers: {
"Content-Type": "application/x-www-form-urlencoded",
},
body: `companion_id=${companion}&no_redirect=true`,
credentials: "include"
});
})();