Mary had a little lamb... had... :smirk:
The idea of Mary is to spawn happy Lambs that jump around distracting defences. Spawned Lambs (the true purpose of Mary) don't have any specific target, they just hop around in random directions although they tend to jump towards the core rather than away from it. They can jump over the walls and are fast enough to dodge shots. Upon death they explode (well, grass eating animals tend to produce sooo much methane :p) dealing damage to nearby structures.
Let's say Lamb's explosion damage is similar to the small Bomb trap (depending on Mary's and TH's levels). Mary herself, as a good shepard, has only a staff, so she attacks in melee range.
Stats can be similar to Witches' - it's really up to devs. I would personally see Mary as a happier version of the dark Witch, same speed and attack power, Lambs move with the same speed as Skeletons, etc.
Why is it different?
I'd call Mary a soft spawner tank - Lambs most often would be in front of golems due to their speed, jumping around would distract defences missing most of the shots. Exploding Lambs would weaken the structures allowing the core main troops to clear the path faster.
There's a bit of luck involved as it would be hard to predict where Lambs would jump. Mary though would walk towards the closes structures, so every spawned Lamb would be closer to the area attacked by main troops.
Attack strategy?
Distracting defences by taking Golems and Giants off the focus and weakening the structures.
Defensive strategy
Distraction again - attacking troops would scatter aiming for the dodging Lambs. Lambs' explosions would be strong enough to kill (or nearly kill) tier 1 troops - maybe similar to the small bomb traps?
Graphic and animation
It's really similar to Witch again, just way more jolly :)
Spawned Lambs could actually appear at Mary's feet
Upgrades
Mary's hp and attack increased slightly every level (similar to Witch)
One more Lamb simultanously every level
Lamb's explosion damage increased every level (similar to bombs?)
Variations
Lambs jump in completely random directions (forwards rather than backwards) or towards the center in a side-to-side manner.
Lambs can choose to feed on grass randomly rather than jump.
Randomly spawned Black Sheep, tougher and jumps towards the nearest defensive structure
Randomly spawned Ram that charges towards the nearest wall one-shotting it (Ram dies on impact)
Pink Fluffy Peacful Lamb that only feeds on grass until death (no explosion)

