Summary:
When a given entity's movement speed is altered, its walking animation would also be changed to match the speed at which it moves, however, this isn't the case with frogs. As a result of this problem, frogs can appear as if they're "gliding" along the ground when their movement speed is set to a high value.
This bug has been fixed in the Java version MC-249129.

Steps to reproduce:

1. Summon the frog.

2. /effect @e[type=frog] speed 1000000 10 true

   Or just hit the frog to make it panic from the damage it takes.

3. Watch the animation of the frog walking.

Observed results:
The walking animation of frogs doesn't change in relation to their movement speed.

Expected results:
The walking animation would match the movement speed of the frog.