The Pokemon Go Valentine's Day event started February 13. Among various bonuses are special field research tasks specifically for the Valentine's event.
The Pokemon Go Valentine's 2019 event provides three time-limited special research tasks. These tasks vary from month to month and are obtained from PokeStops.
Those tasks, and subsequent rewards, are as follows:
There is an overlap here whereby catching Chansey, as a result of catching 20 Luvdisc, also earn you three rare candy. This is also coupled with the event's 2x catch candy.
Spinda, the normal-type Pokemon, is touted to have the possibility of 4 billion unique patterns. At least this is the case in the mainline Pokemon games.
Remember, field research tasks change at a particular PokeStop each day. Therefore, if you can find a friend who has obtained the Spinda related task, then you'll be able to significantly speed up the process.
Pokemon Go events usually offer a number of shiny variants to catch. The Valentine's event is no different.
The pink Pokemon, surprise surprise, Luvdisc, Cleffa and Smoochum are available as shinies. Interestingly, the pink love-heart shaped Pokemon turns a golden yellow in its shiny form.
Feedback since the start of the event shows that the following Pokemon are in the 7km egg pool:
It's worth noting that eggs obtained before the Valentine's event started won't include the increased likelihood of receiving one of these Pokemon.