Axolotls are passive toward players and can be attached to leads. Axolotls give Regeneration I for 100 game ticks (5 seconds) per Axolotl in the fight, up to a duration of 2400 game ticks (2 minutes)‌[Java Edition only], and remove Mining Fatigue when a player kills a mob that is in combat with an axolotl.

To learn more: https://minecraft.fandom.com/wiki/Axolotl