Historical clue formulations

• Playful aquatic mammal — 2026-09-14
• Mammal with webbed feet — 2026-05-30
• Animal known to hold another's paws while sleeping — 2026-04-24
• Cousin of a wolverine — 2025-12-13
• Semiaquatic relative of a badger — 2025-11-11
• River critter — 2025-09-02
• See 39-Across — 2025-08-13
• River animal often seen on its back — 2025-06-09
• Creature with "Underwater eyes, an eel's / Oil of water body," per the poet Ted Hughes — 2025-05-30
• Relative of a badger — 2024-12-29
• Furry swimmer — 2024-08-13
• Pride : lion :: raft : ___ — 2024-06-30
• Playful river mammal — 2024-05-28
• Animal in a romp — 2023-11-23
• Cousin of a wolverine — 2023-10-20
• River gamboler — 2023-06-01
• Playful semiaquatic animal — 2023-05-15
• Shade of brown paint — 2022-11-19
• Animal with webbed feet — 2022-11-10
• With 93-Across, young river critter — 2022-09-11
• Animal in the same family as the wolverine — 2022-08-04
• Animal that's known to enjoy water slides — 2021-06-09
• Mammal that can hold its breath up to eight minutes — 2021-04-23
• A pup is a young one — 2021-04-08
• "Animal House" character named for an animal — 2021-03-30
• Animal known to "juggle" rocks — 2021-01-01
• Web-footed diver — 2020-12-08
• It's said to have the thickest fur of any mammal — 2020-11-09
• Sea ___ — 2020-08-09
• Mammal with a pouch where it can store its favorite rock — 2020-05-09
• Member of the weasel family — 2020-04-15
• River frolicker — 2020-03-24
• Furry swimmer — 2019-12-16
• Animal known to crack shells with rocks — 2019-12-04
• Bewhiskered river swimmer — 2019-06-10
• Playful furry creature — 2019-04-08
• Much-trapped animal in wilderness America — 2019-03-07
• Non-fish aquarium attraction — 2018-10-21
• River gamboler — 2018-09-12
• Den : bear :: holt : ___ — 2018-02-01
• Whiskered, fish-eating creature — 2018-01-20
• Weasel family member — 2018-01-12
• Playful river animal — 2017-12-25
• Animal known to chase its tail — 2017-11-25
• Animal that frolics in streams — 2017-08-07
• Web-footed creature — 2017-07-14
• Playful animal on a stream bank — 2016-08-01
• Oyster cracker? — 2016-07-02
• Animal sought in 2016's "Zootopia" — 2016-05-22
• Lead-in to hound, in the canine world — 2016-02-04