Mateo's comic creation, Z-Blob, unexpectedly follows him from a dream back to...
LEGO Dreamzzz - Trials of the Dream Chasers
Season 1 Episode 8: The Bigger Picture
In the next episode, the kids' quest for test answers leads them to meddle in their teacher's dream, only to discover that Ms. Putnam's gentle exterior hides a darker, more sinister side.