"It was just something that the staff put together. Just a fun thing we were putting on Facebook and it just took off and went viral."
The aquarium has 18 penguins which each have their own personalities and are normally pretty well-behaved, he said.
Timmy was found unable to walk on a beach in Hawke's Bay two years ago and would not have survived on his own for much longer, Mr Yarrall said.
Timmy is now mobile, although a bit wobbly, thanks to treatment and visits from a chiropractor.
He loves swimming and is a rascal who regularly steals fish and pushes other penguins while flicking up sand, he said.
Staff members work with the Department of Conservation to help rehabilitate any injured or vulnerable penguins found in the wild.
The penguins who at the aquarium are either too badly injured or too used to humans to live in their natural habitat.
The naughty penguin board was started about a month ago as something new for the regular customers.
One of his friends Betty was featured as good penguin of the month for being a good swimmer and waiting patiently for fish.
Here are some Facebook comments:
- "The real information we want about penguins."
- "NEW ZEALAND FOR YOU!!!"
- "Look at Betty, she is such a good penguin"
- "Love your Penguins, we watched them for ages when we visited at Easter."
- "Timmy is my spirit penguin"
- "I've heard about this Timmy... Heading down the wrong path. Hanging out with the wrong group, I'm afraid."
- "This is way too cute"