This fic just cracks me up.
What Otter Nonsense (20999 words) by DarkAuroran
Warnings: No Archive Warnings Apply
Relationships: Hatake Kakashi/Umino Iruka
Characters: Hatake Kakashi, Umino Iruka, Morino Ibiki, Shiranui Genma
Additional Tags: OOC (Original OTTER Character) - Freeform, Fluff, omg so much fluff, BAMF!Iruka, BAMF!Otter, Crack, and there’s sex
“Is that an otter?” Iruka asks as large, sable eyes blink at him and a little whiskered nose twitches curiously. “That’s an otter. Why do you have an otter?”
“I can’t tell you,” Kakashi says with a great amount of dignity for a man cradling a baby otter in armoured gloves. “Classified Jounin mission business.”