Another interesting anime the Ansatsu kyoshitsu (Assasination Classrom)
That yellow thing were teacher named by the student as Koro(based on korosenai~ in japanese as con't be killed) at 3-E class.
the student need to think how to kill that teacher,and it won't be easy that KORO sensei can move at top speed 20Mach(same as 24501kph
). Student need to kill it before next march The teacher has just destroyed the moon and is threatening to destroy the earth – unless his students can destroy him first. What makes things more complicated is that he's the best teacher they've ever had!