Neopets, never change.
The Feat[]
A blumaroo picks up a tree and uses it to hit a doll... seriously.
This happens on the game Kass Basher, there is a 1 in 1000 chances that if you pick the hardest difficulty , you will get a tree instead of a bat .
According to this chart, a Blumaroo is 1 meter tall. http://neocolours.me.uk/petsizes.php
In this image. The Bluemaroo is 95 pixels tall, the tree is 427 pixels tall, that makes the tree 4.49 meters tall and it is 61 pixels wide, or 64 centimeters.
http://www.online-calculators.co.uk/volumetric/cylindervolume.php
Using the volume of a cylinder, the tree is 5780041.142857138 cubic centimetres.
Using the density of wood... I decided to use the value of an oak tree, or 590 kilograms per cubic meter, or 0.00059 kilograms per cubic centimetres. https://www.simetric.co.uk/si_wood.htm
So. Mass = Volume x Density
So Mass of tree = 5780041.142857138 x 0.00059 = 3410.22427429 kilograms... or 3.759128790338779 short tons.
The Kinetic energy might be off...
The average swinging speed of a MLB player is 70 miles per hour... so let's say this guy is swinging at 20 since he is super small, plus he doesn't seem to have any trouble with the tree. https://blastmotion.com/blog/baseball-swing-speed/
http://www.csgnetwork.com/kineticenergycalc.html
The kinetic energy of that tree hitting something would be around 136,303.09 joules. Easily Wall level.
For comparison, if a Volkswagen Beetle with a weight of 800 kilograms ran you over at 40 miles per hour, it would only release 127,900.64 joules. That is 8,402.45 joules less.
And note, that is an AVERAGE NEOPET.