Axolotls are Minecraft's newest mob addition, having come in with the game's Caves & Cliffs update, and they can be beneficial in combat for regeneration purposes, in addition to their cute appearance.
Feeding them can be a little tricky though, as they will only take buckets of Tropical Fish. If Minecraft players attempt to give them standard Tropical Fish, Axolotls won't take them.
This is as per a dev diary where Mojang explained that this was intentional, due to Axolotls enjoying live fish in real life and not eating dead ones. So in order for players to feed their Axolotl, they'll need to craft some buckets with iron and set out to capture some Tropical Fish.
Minecraft: Where to find Tropical Fish for Axolotls
Fortunately for Minecraft players, Tropical Fish aren't too difficult to find. With over 2,700 naturally-occurring variants, players are likely to find a few within the ocean at some point.
According to game data, Tropical Fish spawn in groups of eight at 24 to 64 blocks away from the player. As long as the ocean is warm or lukewarm, Tropical Fish are likely to spawn there, as they don't naturally spawn in frozen bodies of water.
Tropical Fish travel in schools much like real life, and players seeking to capture them will first need to craft a bucket with iron ore and fill the buckets with water. Once they've got their buckets filled with water, it's time to set out and find a school.
Upon finding a school, all Minecraft players need to do is use the water bucket on the school of Tropical Fish. The fish will be captured in the bucket, and players can head back to their Axolotl and surprise them with a treat. Once again all players need to do to feed the Axolotl is to use the Tropical Fish bucket on them.
Players may also use Tropical Fish buckets to lead Axolotls around, as they will follow the player as long as it is held, similar to cows and sheep following players that carry wheat in their hands.
Feeding Axolotls Tropical Fish buckets can allow them to breed as well as speed up the growth time of babies. Each use of a Tropical Fish bucket on a baby Axolotl will speed its growth rate by 10%. Having friendly Axolotls can be a big help in Minecraft, as they supply not only health regeneration and the removal of mining fatigue, but assist in battle as well.