The ornamental design for a babytoilettrainer, as shown and described.
FIG. 1 is a top front perspective view of a baby toilet trainer showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom perspective view thereof;
FIG. 4 is a rear perspective view thereof; and,
FIG. 5 is a left side view thereof.
The broken lines and unshaded regions of the remainder of the baby toilet trainer are for illustrative purposes only and forms no part of the claimed design.