Mega Mush

Effects

Gigantifies Isaac for 30 seconds, persisting between rooms. While Gigantic, Isaac gains the following effects;
- Gains a 4x damage multiplier and ~+7 range, but a 2.5x tear delay multiplier.
- Becomes invulnerable to damage.
- Can destroy obstacles and objects and open doors by walking into them. This includes metal blocks.
- Deals extremely heavy contact damage to enemies (80 per tick, or 1,600 per second).
This item belongs to the Fun Guy set. Collecting three items from this set will transform Isaac into a walking mushroom.

Using Mega Mush again while its effects are still active will add an additional 30 seconds to the current active time.
Isaac's physical size, i.e. collision circle or "hitbox" is roughly doubled in radius when Mega Mush is active. This is the only item that can make Isaac tangibly larger than his starting size, as normal size ups can't increase the collision area beyond the default.
Mega Mush will not negate the damage taken from the Mausoleum door. It's even possible to die this way, while the item is active.

4.5 Volt: The contact damage dealt by Mega Mush will allow you to recharge it and use it multiple times in the same room.
Car Battery: Mega Mush's active time will be doubled to 60 seconds.