Pupils at Great Dunmow Primary School dressed up and took part in activities to raise money for Children in Need.
The costume theme was 'spots' and 'wild and wacky', and children took on their class teachers for the 'reindeer antler challenge'.
The challenge involved teachers trying to get at least two rings on the antlers, and if they failed they were hit with a pie.
Headteacher Kevin Watts said: "It was a great day and lots of fun.
"We always do something a little bit different for Children in Need and apart from a non-uniform day, we asked our school parliament what they would like and they overwhelmingly said something that involved custard pies.
"Parents' donations have already topped £400 and we are still collecting."
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