Stampeding Scurryfoot
Creature — Mouse
Exhaust — 
: Put a +1/+1 counter on this creature. Create a 3/3 green Elephant creature token. (Activate each exhaust ability only once.)
All creatures great and small contribute to the stampede.
Julia Metzger
Aetherdrift (DFT)
• #181Rulings
If an ability triggers whenever you activate an exhaust ability, that ability resolves before the exhaust ability resolves.
(wotc • 2025-02-07)
If an exhaust ability of a permanent is activated, and then that permanent leaves the battlefield and returns to the battlefield, it becomes a new object so its exhaust ability can be activated again.
(wotc • 2025-02-07)
Exhaust abilities can be activated any time you could normally activate an ability.
(wotc • 2025-02-07)
Rulings
If an ability triggers whenever you activate an exhaust ability, that ability resolves before the exhaust ability resolves.
(wotc • 2025-02-07)
If an exhaust ability of a permanent is activated, and then that permanent leaves the battlefield and returns to the battlefield, it becomes a new object so its exhaust ability can be activated again.
(wotc • 2025-02-07)
Exhaust abilities can be activated any time you could normally activate an ability.
(wotc • 2025-02-07)