I am playing Lego Harry Potter Years 1 - 4 in two-player co-op on the Nintendo Switch.
In the courtyard where you are first introduced to broomstick flying, I was running around on the ground with Scabbers trying to figure out how to dig in the special patches of soil (it turns out that Scabbers can't do this). While mashing buttons, I somehow ended up mounted on a broomstick with Scabbers. Like Harry, Scabbers was able to fly the broomstick with full control, though of course he couldn't use a wand. While the broomstick moved, Scabbers would continuously play his running animation.
I thought this was an intentional feature the developers put in so that both players could fly a broomstick with full control, rather than one player being stuck on the ground while the other controls Harry. However, after hopping off of the broomstick, I wasn't able to get back on it with Scabbers.
I've spent a good 20 minutes trying to get back on a broomstick with Scabbers, with no success. Was this a bug or one-time gag, or is there a special trick to getting Scabbers to mount a broomstick?