When encountered, Skullys attack with their sword and will occasionally use their Whirlwind Shock special to tear through your lines. This makes them a very dangerous threat when they can get close enough to your troops. Unlike his opposite, the Knight, his main function is offensive and aggressive attacks. The most effective way to kill them is defensively with the Elf's arrows so they're unable to get close enough to attack or use their special. On the lower levels they don't use their special that often, making them less of a threat.
His stats are based on that of his opposite, the Knight. They are defensive monsters and so use an defense boost. They have normal movement speed, attack with the low/med power, have a cheap special, and have low HP.
In tiers 1-2 Skullys share an identical special named the "Whirlwind Shock". During this special he twists himself to an tornado and goes berserk, hitting every unit that he touches. This special is only effective in close combat, but can easily can hit multiple units. It's a special that he can easily spam on your units, which makes it relatively dangerous and annoying when he uses it; mostly when you use the Forward Arrow.
On the first levels they don't use their special. They start using it on 1-7 for Funny Bones and higher for regular Skullys.
An non-upgraded Tier 1 Knight has almost the same stats as a Skully on normal difficulty.
They upgrade to Tier 2 later in the game.
Tier 2 Skullys have boots.
You can control Funny Bones with a Tier 3 Healer. Unfortunately, doing this makes 1-7 impossible to finish, and the level must be restarted.
The Skully Boss can also be controlled by the healer, which makes levels like 1-2 impossible to win without restarting.
Some say that Funny Bones really can be an pain in the neck when he spins through your lines when you're in offense mode. He takes your Elves out in a second swing, especially if you didn't upgrade their HP, so be careful. Most players underestimate Funny Bones when he comes back to life at the last area.