Spiders will always suffocate when spawned from dispenser. Tiny slimes wont, and other sizes will suffocate frequently.
Related issues
Comments
migrated
migrated
It sucks. I would have liked to use this mechanic in an adventure map.
migrated
I think it should be fine if you have the dispenser below where the mob spawnsw
migrated
Does MC-8293 describe your issue?
migrated
Not exactly tested it with the dispenser in the wall. There were no blocks behind or in front of it just on all the other sides
migrated
Please respond to the question.
migrated
What do you mean? Didn't I just do that?
migrated
Is MC-8293 the same issue as yours? I am just looking for a yes or no answer.
migrated
It's a related issue, it's caused by the mob being spawned in a position with it's hitbox in a block.
dispenser == solid block
head/hitbox in solid block == suffocation damage
migrated
Is this still a concern in the current Minecraft version 1.7.2 / Launcher version 1.3.4 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
migrated
It probably is, but it was mainly used for adventuremaps etc, now you can use commands to spawn in mobs, so using dispensers for adventuremaps is a little redundant.
Ezekiel
This ticket is incomplete without the requested information, no response has been received within a reasonable time and we are assuming the issue has been resolved. Should your issue return please submit a new complete ticket with all available information.
Please review the guidelines before reporting issues.
Confirmed, their hit boxes clip into the dispenser, sometimes(or all the time) keeping them from moving.