Donald Trump forgets his age, then pretends he's a duck at Pennsylvania rally (video)

Last week, Donald Trump forgot he was at a town hall in Pennsylvania, lost in music as he bizarrely swayed back and forth on stage for 39 minutes. Now he's impersonating a duck.

His quacking occurred at a rally back in Pennsylvania yesterday, when he was talking about fracking and suddenly went into character. "So we're going to let them frack! Frack! Frack!" he quacked, bending into a duck pose. "Like a duck. Frack! Frack! Frack!" (See video below, posted by Acyn.)

His duck imitation came after the 78-year-old candidate seemed to forget his age, telling the crowd, "I'm not 80 and I'm not that close to 80." It also came just hours after impersonating a McDonald's worker while the fast-food restaurant was closed. Sadly, it's common for people struggling with dementia to exhibit toddler-like behavior — but most don't run for president.

And for a reminder of last week's excruciating glitch, see video below.

Previously: Trump's sleepy in-court off-gassing may be additional signs of dementia