When multiple glass bottles are used on a dragon fireball or the dragon acid attack, the radius of the corresponding area effect cloud can become negative. The dragon fireball, upon reaching a negative radius, is removed. However, the dragon acid does not, giving it an appearance of 'growing' in size as more glass bottles are used.

This is possibly because the acid attack's area effect cloud is designed to be persistent for a certain time period, in contrast to the dragon fireball which can be 'depleted'.

Steps to Reproduce: 

1: Go to the end, and turn entity hitboxes on.

2: When an area effect cloud is created by a dragon fireball, use glass bottles multiple times. Alternatively, use a clicking script.

• The area effect cloud disappears as its radius reaches 0  
• (if a clicking script is used that sends more than 1 packet per tick, an area effect cloud with negative radius could be seen for 1 tick before being removed)

3: When an area effect cloud is created by a dragon acid attack, use glass bottles multiple times. Alternatively, use a clicking script.

• the area effect cloud visually shrinks, but then grows as more glass bottles are used. The negative radius can be confirmed by using:

  /data get entity @e[type=minecraft:area_effect_cloud,limit=1]

• The area effect cloud does not disappear until dragon has finished its attacking sequence, and if continued to be 'used', will continue growing